Ill try these codes so far and see what happens. If you can, please use my save date here, There are 3 different health types for a start, Red, black and souls hearts. Not certain if a universal, or individual health cheats are needed. Like you say stuff might be shared with enemies so this could be the reason for the crashes.
Some info if it helps you. The characters, Isaac, Magdalene, Cain, Judas, Eve, Samson, Lazarus all have red hearts. Lillith has 1 red heart and 2 black hearts, Azazel has 3 black hearts, ??? has soul hearts and The Lost has no health.
I found out that the codes above are not 100% ,crash is also included here. I'm sure it must be a Level 4 Pointer Negative code but unfortunately I can't search for it because it takes a hell of a lot of power and UPS crashes.