For some reason I didn't get Phantom at all in my completed AP game, but I can see that using it on Paladins would be devastatingly effective. In fact, for a Warrior who doesn't really have the Mana to cast Resurrect a lot, Paladins and the Time Back spell more than compensate.
I agree that money is plentiful, at least on Hard. At the end of my game I still had pretty much every item I'd picked up, because I was loathe to sell them for such a miserable price. Still had plenty of money without selling them. That's a good idea about the Marauders finding money - I was using the Baby Dragon's treasure finding a lot in the early/mid game, until I realised it wasn't necessary anymore.
But it is a little disappointing to hear that no losses on Impossible is relatively doable. I think we all hoped that AP would be a little harder than TL, but I see no evidence of that. For me the fun is not in trying to complete the game in the quickest possible way, or with zero losses (although I may try this at some point), but simply to relax and have fun with the game, trying out different combinations of artifacts, spells and units.