I have to say I really like the wizards spell mechanics.
What I would like to see is to be able to gain possession of some new unknown spell.
It says new spells are researched constantly and it would be sweet if one could gain newly researched (or long forgotten and lost) spell who is unknown to enemies and so they can't use it.
It wouldn't have to be all-powerful spell, just something nice, gimmicky and situational, maybe more specialised variant of standard spell.
Also if there are some NPC wizards, you could sell them knowledge of that unknown spell and although it would net you nice sum ofm oney, it would also mean it becomes more widespread.
Also, I really love the inn, it looks great.