Nice to know there is a like minded person out there, I was thinking of adding some summoned enemies when fighting a lone monster but it might not make much difference in the big scheme of things. I removed the lone demon wanderer from the swamp, the easiest target, but capturing any high level monster for sale or combat is still pretty good. Moving the amnesia potion to the second tier of alchemy lab just postpones the issue. I'll keep thinking on this but it's hard to sort out the core problems and what sort of tweak would actually help most.
I haven't given the game past the end of story mode much thought and this mod actually relaxes the shopping restrictions at the end of the story. I'm guessing you can get close to the income limit fairly soon after beating the main quest and then it'll just be a case of repeating that each week until any increasing debt mechanism finally wins out. I'm not sure I'd want to test it! Maybe it's something you could request for the main game?