Apart from players not knowing how their abilities work, this is the number one pace-killer I see in games.
It's compounded with larger tables - in my games with 7 or 8 players, I see so many players when we reach a decision point who try to fade into the crowd, wanting another player to make decisions and take risks so it won't be "their fault" if (decision x) turns out to be a bad move. So they get paralyzed. I always feel like, you know there are zero real-life consequences at stake here, right? Just drink the potion.