(Unless y'all can figure out why my summoning dolls won't stay summoned. Then please, enlighten me. I'm desperate!)
The dolls are on a time limit (very short one in some cases). They flash red just before they are going to disappear. They are really only for tough battles as a tank to take the damage or as an extra hitter on the side. I just use my summons as mules, put all heavy items I don't use on them and let them 'unsummon' after the time limit. All stuff on them is there when I summon them back. Like an extra backpack.
The skill menu is just how you said; if you don't click the tick before exiting the menu, it takes it as you cancelled your actions. The tick button is like "accept" I guess, and the cross is "exit". I've done this a couple of times and had to re-level up.
Unlearning skills is a lot easier in act 3+, money is a lot faster to get. I usually have too much and as merchants dont restock, I have nothing to spend it on. At the moment I have over 260,000 gold. So I experiment with different skills etc. Money really isn't as scarce as it was in Divine Divinity. Later anyhow.