Regarding the Mega Trainer, Unlimited Health, Zero Enemy Health....
I can use the 1.3 trainer sparingly. I guess the most important factoid I have found is this:
Just start the trainer, then the game. I have only used the F7 key, but that makes you invisible,l so at least you can wackulate the bosses, and there is a good one, in the dungeon, level 5, in Athens. First make sure you have the mouse engaged, and then hit the F7 key, it will hesitate, but then, alas, you are invisible! And as we would say in Naw'lins Whomp, there it is!