Is it possible to have every blaster shot hit?
Regular Attack and Rapid Shot fire a number of blaster shots, only a few of which ever seem to hit. Is it possible to have such a high dexterity that every shot hits (ie. all 6 shots of Rapid Shot, all 3 shots of Regular Attack)?
No, this is not possible.
A regular attack with one weapon is resolved as a single roll which either hits or it doesn't, and then an appropriate animation plays, which may consist of multiple shots or strikes. However, these aren't considered separate attacks - they're all part of the same hit.
If you do have multiple attacks in the round, by using Rapid Shot/Flurry or multiple weapons, it will still only animate one of them (the first, I think). The other attacks are calculated and applied but not shown.
It's helpful to remember that, aside from movement, KotOR's combat is basically turn-based thanks to its D&D heritage. An attack isn't a single bolt but a full-round action.