Again, you are venturing where few modders have dared tread, so I wish you the best of luck and success on this! I'm just an .xml jockey myself, and I'm trying to remember what it was I wanted to 'fix' back in the E:WOM days that required an interface change...
My tech tree consolidation mod (changing from 5 tech trees to 4, plus the fifth tree that redirected tech points to arcane research or gildar as I remember) for E:WOM ended up working pretty much as well as hoped, but as no one really plays that game anymore, wrapping up that mod hasn't been a priority, since it would probably be for just me...
Ahh, I think I remember now. I was trying to create a spell that allowed the caster to learn a spell list or something... this was only supposed to work once, but unfortunately I couldn't quite work this out. Don't remember all the details, but it involved the character creation interface, and possible duplication of spell lists as I remember... unfortunately, the flurry of patches resetting all the files constantly at that time, and the beginning of 'hack a feature' burned me out and I set this mod aside. Heavenfall and others did try to help, and I also had another issue with the 'calc' feature not working for items. Spell effects don't work well as always on items using stats as bonus modifiers, such as a ring that adds 30% of your con to your defense, long story but a long standing/lingering issue that Modders have been hoping for a solution for. Sorry, rambling on there.
Again, very much looking forward to your progress on this. If you could keep this as a standalone (deals with Dynasties only), I'm sure a lot of modders would love to use this along with their own mods!