My main feedback is that Larian should NOT kill/remove companions at the end of Act 1. At the very least, not arbitrarily "everyone not currently in your party dies" like in DOSII.
Yes, I find it really hard to believe there's a way to get rid of all but a few companions all at the same time at the end of act one that's not going to feel really forced and artificial. At least the DOS2 shipwreck kind of made sense, but they can't pull that trick twice.
I have no problems with companions drifting away and going it alone at individual story-relevant points if you fail to help them, or they can't stand you. It would make sense for Lae'zel to take off if you don't head to the creche in good time, or Wyll if you fail to follow Mizora's trail, and we know Gale already has other possible irons in the fire if we don't feed him magic items.
Hopefully a forced focus on one party is an idea that Larian will dump in response to feedback. Or perhaps they'll come up with an absolutely compelling story for why and how the party gets whittled down and I'll eat my words, but they'd need to pull an absolute stunner.
And, as mrfuji3 says, even if we don't have more than three companions the indications are that we could have mercenaries that would make handling more than four possible party members a necessity either way.
