Not sure about adding other icons. It's something I'd like to do for Scales too. I assume you've seen the various .dds icons files which you can use to see all the icons? As far as I'm aware, the talentsAndAbilities icons are unused in the PC version, so you can use those for some skills.
For the treasure table, you can just prefix I_ to specific items in the table, no need to define them that way originally (you'd just have to input I_I_SKILLBOOK_FarSeer in that case).
