Not exactly. I like PoR, but FE 7 was way better for me. Hmmm, regarding if the game changes with the death of a character, I don't think so. They are only lost forever. Be afraid when you use the main characte and another character later in the game, if they die it's game over and you must restart the chapter (As always).
As for the problem I told you, I don't think so.
I've been looking for a way to identify them, but with no results.
The easiest way to notice this is if you have a PoR archive in a Memory Card and you try to transfer data with an Easy Mode playthrough. The game will freeze. If the game is a recent copy then there should be no problem with this.
I wish I followed my father's advice and waited a bit to buy RD, instead of buying it as soon as it was released.