I don't know if you are familiar with 5e but I think cooldowns would be a mistake. I think one of the biggest mistakes Larian made in EA is not including level 5. It's a major bump in power for the characters and people who are unfamiliar do not understand what lies ahead. Martial classes get their second attack. Casters get 3rd level spells. It's the reason why levels 5-10 are considered the sweet spot of D&D PnP. You have just enough powers to make things interesting and you aren't bogged down with too many powers that drag out combat.
They really should let the players experience level 5 in early access. It would clear up a lot of confusion.
