Has anyone looked up during the trials to see if there's anyone sitting there and if not, what is the role of the place? I have not actually checked, but based on my experience in other Dwemer ruins, I'd be completely astonished if this were the case. Numerous NPCs and in-universe books repeatedly emphasize that the Dwemer vanished long before the events of Skyrim, and we never encounter any living Dwemer at any point in the game. I suppose it's theoretically possible that a member of one of the extant races of Tamriel might be up there, for some reason, but I'm not aware of any plot points which relate to such a thing. Regardless, the Dwemer probably didn't intend those chairs to be used by anyone other than themselves. Did the Dwemer use it as an arena to test their subjects and to what end? Similar chairs overlooking torture devices, arenas, and related paraphernalia can be found in Blackreach (in multiple places) and Bthardamz (the Lower District), and probably in other places that I'm forgetting. Based on some of the lore in Dawnguard (particularly their treatment of the Snow Elves), it seems like the Dwemer were not very nice people, in general, so it seems plausible to me that these devices were used on living subjects of some kind. Much of the lore emphasizes the Dwemer's focus on reason and logic, so I imagine that some form of scientific experimentation is the most likely explanation for these structures. For more specific information, I would suggest consulting UESP's article on the Dwemer, and some of the in-universe books it links to.

I'm assuming you are asking if you can fly to Solstheim, the main area in the Dragonborn DLC. If that is the case, then that is not possible. As travel in any one direction is not possible, dragons cannot be used in place of a traditional mount, such as a horse. It is possible to fast travel while mounted on a dragon, however travel between Skyrim and Solstheim is not possible Dragon Riding wiki

You only need to place the four books you have found up to this point. You should then be able to activate the book on the fifth pedestal in the middle of the structure, and warp to Chapter VI. Provided, of course, that you put the books on the right pedestals: Boneless Limbs is placed on the 'tentacle' symbol. Delving Pincers is placed on the 'pincer' symbol. Prying Orbs is placed on the 'eye' symbol. Gnashing Blades is placed on the 'fangs' symbol. For PC users, if the pedestal still won't activate, you can use the console command coc DLC2Book01DungeonEnd01. This will send you to the Chapter VI area immediately, and trigger that part of the quest. For console users, I think the only fix will be to load an old save. Source

The DLCs as well as the original base game have been hidden, but are still accessible. This happens with other games as well when a remastered version is released. If you had previously owned Skyrim: Dragonborn through steam, you would have automatically received the Skyrim: Special Edition, which is the remastered, all encompassing version of the game, at no additional cost when it was released. Once that version was released, they hid the original from the store. Thankfully, I still have the base game in my library and was able to pull up the direct link to the DLC purchase page as well as a free texture upgrade patch. You can find those here and if you already own one of the DLC packages, it will say "already in library". The base game is located here. Give it some thought thought: Special Edition runs $40 whereas the DLC packages for the original version cost $45 ($40 of that is between Dawnguard and Dragonborn).

Just finish Miraak's questline, and you will get your souls back. There are no places where you could farm dragonsouls, without the chance that Miraak will steal them. However, the shouts you need for the questline will be unlocked without needing dragon souls.

Skyrim Special Edition comes with all DLC already included. You don't need to buy it separately.

According to UESP The door prevents access to Neloth's staff enchanter and an arcane enchanter. It is possible to buy unenchanted staffs from Neloth and create your own staffs using the staff enchanter, but only if you prove useful to Neloth by completing a quest. This room also contains a Black Book titled The Hidden Twilight reading this will initiate the quest of the same name. The quest that needs to be completed is The Reluctant Steward in order to unlock the door with the black book.

Pickaxe from Crescius is not needed to complete this quest, but it does collect Stahlrim inside Raven Rock Mine (the place of the final descent quest). I will still tell you how to get it in case you have not started. You must discuss with Glover Mallory a Corberoc walker (if my memories are good he is a blacksmith). You must discuss with him about the pickaxe, he will tell you to go and force Crescius to hand it over. The old man will not refuse you, once you have spoken to Crescius you return to Mallory who will give you as a gift the pickaxe.

I am at Solstheim for the Dragonborn DLC and I want to go back to Skyrim. The problem is that I don't have enough money to go back and forth. Once you reach Solstheim for the first time, you'll get fast travel points unlocked on both the Solstheim and Skyrim world maps. They're roughly in the lower left and upper right corners, respectively. Using these lets you fast travel as normal between the two continents; it costs no money, so your lack of funds should not be an issue. I have many items on Solstheim that I would like to take back to Whiterun. What is the best way to travel with all the items? I am trying to travel to Skyrim with all the items, but it doesn't let me do that. Any way to avoid this? Fast travel as above is subject to the usual restrictions about being overburdened (i.e., you can't do it when you're carrying too much). If you're having trouble with the game "not letting you" bring all your items back to Skyrim at once because you're overburdened, either store some in a safe container and bring them over in batches, or drink a few potions that increase your carry weight beforehand, or get on a horse. Additional notes on various other ways to circumvent carry weight limits can be found at UESPWiki.

Solstheim is a big place with 8 Arcane Enchanters. There are even 3 in Raven Rock: Councilor Morvayn's house, Ravenrock Mine & Severin Manor. My 1st thought would be to go to Tel Mithryn, where you also have ready access to supplies & training. Best of all, the door is never locked.

No, there is simply no way to finish the quest without killing Miraak. Furthermore, there is no way to kill Hermaeus Mora (in the base game/DLC, at least). However, I found this oddly specific mod that apparently allows you to do exactly what you've described in the question. The mod allows you to cast Bend Will on Miraak and team up with him against Hermaeus Mora, as well as unlocks Miraak as a follower and marriage candidate. Unfortunately, nothing on the page indicates whether or not this mod is compatible with Skyrim Special Edition. This appears to be a port of the original mod that works in the Special Edition, but it looks like it was combined with other mods.

Based on the data available here, your choices are correct: Chaos damage applies the base 10 pt. damage to all three elemental effects (triple damage) but with 50% chance, making the average DPS about 1.5 times the damage of using a single elemental effect. Fiery Soul Trap gives you the standard 10pt. damage that you get from the Fire Damage effect with the added benefit of soul trapping. However the fire effect is NOT augmented by your enchantment skill or perks. It is increased by the Augmented Flames Destruction perk, however. And Frost damage is beneficial as it slows down the enemy which is useful against the majority of enemies (excluding trolls, frost atronachs and frost wizards), as well as the 10 pt. base damage. If you are playing a vampire, you can further increase these effects using the Necromage perk (+25% magnitude on enchantments) and by levelling up your enchantment skill and choosing appropriate perks.

Miraak does not always steal your souls when you kill a dragon in Skyrim. Also, if you happen to kill a dragon above water, then Miraak will not appear and steal your dragon soul.

The door will only unlock if you complete the quest "Reluctant Steward". Here is a reference page for the book in question: http://elderscrolls.wikia.com/wiki/Black_Book:_The_Hidden_Twilight_(Book)

There's a mod specifically designed to remove the Black Books from your inventory, which you can find here, though I do not know whether you can use this mod on the special edition or not. (As an aside, according to the page for the mod, this mod has caused 0 computers to blow up, so that's a good sign it won't break your game.) If you don't want to use a mod, it looks like you could also use console commands to remove them from your inventory (as well as add them to a container). The relevant console commands would be: player.drop [item ID] and additem [item ID] [quantity] The item IDs for the black books are XX016E2C, XX01E99E, XX01E99F, XX01E99D, XX01E99C, XX016E2D, and XX016E22. It's worth mentioning that according to a user here, picking up one of the books again will cause you to be teleported back to Apocrypha, so be wary of that if you choose to put the Black Books somewhere other than your inventory. Now that I've messed with it, I realize there is a very good reason why the Black Books remain quest items forever. If you were to drop one, you wouldn't be able to pick it up without getting sent to Apocrypha. Also, this sort of goes without saying based on the nature of the books, but you most likely want to be completely done with the Dragonborn questline before removing these books from your inventory, or else you might break something.

Return to skall the quest should go on normally

From what I've seen, it looks like you're only able to heal your horse while you are standing next to it, rather than riding it. As for healing your dragon, based on the Healing Hands wikia page, it looks like it will work for your dragon mount, since dragons are not listed as exceptions. It will not heal undead, atronachs, or Dwemer animunculi. However, you can't cast it while riding, as it's not listed on the list of spells/shouts you can cast/shout from dragonback here.

I looked it up again recently, and I found the developer's answer to this question. Evidently, he is one of the few merchants that do not have merchant chests. I cannot find the page again, so I can't link it.

If you have not completed the main questline and defeated Miraak, you cannot accept any new missions from the Skaal or complete any missions that you may have already received.

this may be because you have bounty in raven rock. trust me this has happen to me before on other missions so your best bet is to check your bounty in the main menu and then go to raven rock and either pay it off or get arrested. once you have done that try again and they should not attack you.