After playing for a few days on patch RC15b5, I have a few questions.
On the default difficulty, in the city selection menu on the map, city rebuilding was unavailable in the game: after capturing castles and selecting the city rebuilding option in the book of travels, the game reported that the rebuilding skill had been acquired, but nothing else happened; it also stopped displaying the required number of resources needed for rebuilding.
First part of your message: Do you mean that the Town Management spell was not available in the hero's spellbook and randomly appeared at some point in the game?
Second part: Town conversion was executed, but no conversion happened. Were resources deducted from the player?
Another question: is it a bug, or is it intentional, regarding the guards on resources: you only need to pay once; if you capture a mine guarded by guards, you don't need to pay again, and a new one will appear next week; after capturing a mine with existing guards and then recapturing it, the number of troops next week will be identical to the number of troops in another mine that was not captured, instead of starting the growth count over.
Checking with the team...