Do custom games of a higher difficult count for those below it for the custom games vs AI achievement?
For the Custom Game achievements (i.e. get 10 wins as zerg vs medium AI opponant in a 1v1, etc etc) do you actually need to grind out a bunch of games vs a medium AI or can you just fight the hardest level AI and have that count for all of them?
After a couple games I've realized it's impossible to loose vs the Medium AI and this has made it boring..
Yes. There are several categories in the "Custom Game" achievements where playing on higher difficulties gives you credit for lower ones. I can personally attest to the Outmatched and FFA-vs-7 achievements working, since I beat them all on Insane first and got credit for the easier versions.