Lower Prestige should have real consequences, though. It's supposed to be tied to nobility, so it should lead to higher political corruption, assassination attempts, etc. There's already another stat for lewdness. As it stands the only person that cares about the Queen improving her Prestige is the Duke but I thought that would change. (Mena only cares about the status quo.)
As for money, once again I'm thinking in the long term. If the game isn't even halfway through, the amount needed will increase much more as the game goes on. And once new content arrives, for various reasons the tribal war will just become a grindwall. The only way to speed past it right now is through debt. Is using the bank is supposed to be a non-negotiable cornerstone of gameplay?