1) Bank balances. I know this is a "premium perk" so I'll understand holding it back, but it seems not Trader like to not include basic information like my balances in various banks and in my shop in my ledger.
2) Some kind of listing of a) shops we can finance b) stables we can put our caravans in c) "normal" gem shops and furriers d) horse selling locations (I know they're barely used because horses are so meh, but that's all the more reason to have a listing of where to go if the rare incident of needing on arises.) and e) locations for functioning auction halls.
We have all these systems, and while there are 3rd party resources (Elanthipedia, Mytwokronars.com, Lostonawhim.com, etc) it seems to me a lot of this stuff should be added to ledgers. It makes sense for the info to be in them, and there's been a pretty large influx of people trying the guild lately.