You misunderstood. The whole conversation in this thread is about how casting a spell looks like. Not how your full list of spells looks. So again a wizard casts from memory. He doesn't take his book out of pockets in a middle of a fight to read a spell from there.
No, most images here are from UI that tell you what spells this character knows, not how you cast them in normal gameplay.
So a book in case of wizards is totally fine.
I would also say that all classes need the same UI, because in 5E all classes with spells ( except warlocks ) use the same casting system.
I also think it makes sense to put all active abilities in the same menu so you can put them into the hotbar however you like.
So the spell menu should have the following categories:
- class abilities: Everything that can be used and you got it from a level up.
- item abilities: The special attack given by weapons and all spells or abilities that are given to you by the stuff you have equipped
- Spells sorted by level, from lv0 to 9
- In case of warlocks, all spells known from lv 1 to 5 are always shown in the highest lv they know and old spells move up automatically when you level up.
So a warlock of lv12 or higher has only cantrips (lv0), lv5 spells (here are all spells from lv 1-5) and then come lv6 spells and so on (can only be used once per day, but its still a lv 6 spell or higher)
Once again, I would prefer having the NWN2 menu for actually casting a spell instead of using a hotbar.
Prof. Dr. Dr. Mad S. Tist 
