Mainly looking at Aracana, Stealth and Mechanics I guess. Don't think I need to worry about anything else as I can have other party members do those things. In POE1 I'm easily getting away with a 5 in stealth.. (with gear boosting it to 8)… I can sneak / steal / scout around quite easily. No idea if that's sufficient for POE2. Mechanics obviously need to be the highest. Have no idea how much skill boosting gear there is in the game for mechanics. Arcana is the one I have no idea about. How
30% hit->crit is not a lot for something you actively spend resources on (versus a passive or item buff); the expected value of the bonus crit damage from barbaric blow is still pretty mediocre, only barely above crippling strike in terms of damage potential and ignoring the other benefits to crippling strike. you get way more form the bonus pen as a situational underpen ability than trying to rely on critting.
even at 1 cost, alluded above crippling strike serves several other