I haven't read every mind, since I'm too afraid of loosing too much XP (I don't want to cheat and use a mindreading guide in order to find out whom to read minds on).
I have 2 in lockpicks and can open about ½ of the locked chests. I try to go into every building and talking to every NPC. I go into every trapdoor I can find.
Sure I will miss some sidequests, but as far as I know, I have taken the vast majority of them until now.
Still I play as a Wizard and the game will probably play very differently with a Warrior.