I suspect you will want to test some of those changes in order to see what impact they will have on the AIs behaviour before modifying all the files. While some of these might be great restrictions for a human player they might lead to some mighty peculiar behaviour from the AI. Especially given its habit of recruiting stacks and sending them to stand around doing nothing for turns at a time. Also, I would have thought you might need to modify the starting positions of many factions in terms of what troops they have. Some of the barbarian factions will go bankrupt immediately with your proposed changes and never recover or expand. Maybe only edit the unit upkeep costs for the faction you intend to play and leave the AI as is?