Unfortunately I don't have much time for BotE, haven't had for the last 3 years, but I do fix bugs occasionally.
Yes, you can't cancel an Alliance, I think it's intentional from the original design (I only picked up development a few years ago).
As for the trade routes issue, only a save might solve the mystery, drop me an email with it to boteandroid@gmail.com , and write me the exact instructions on how to reproduce it, hopefully I'll have time in the next few weeks to look into it.