and if a given character is in my dead pile in 2 copies, I assume this overrides the regular rules and allows me to put him into play?

No.  You cannot put into play a copy of a card in the dead pile, and this "cannot" rule beats any other card effects such as this one.

From the "Dead Pile" rules:

A single instance of a unique card in a player’s dead pile does not prevent an effect that would cause the card to enter play directly from the dead pile. This is because such an effect removes the only instance of the card from the dead pile.

 

To clarify, if *you* cannot put a character into play, that does not prevent *your opponent* from doing so.

To clarify, if *you* cannot put a character into play, that does not prevent *your opponent* from doing so.

so to clarify further (opps = opponent's):
1) when i put into play a unique character from my opps dead pile - I put it under my opps control?
2) if my top dead pile unique character is in 2 copies in my dead pile - I cannot put him into play?
3) if my opps top dead pile unique character is in also my dead pile - I cannot put him into play?

4) if my opps top dead pile unique character is in his/her dead pile in 2 copies but not in mine dead pile - I cannot put him into play

5) and if my top dead pile unique character is the same one as my opps top dead pile unique character?

I know... kind of absurd but I do not want to loose a game only because I understood it differently than my judge

quoting rules:
xxA player cannot marshal, play, put into play, or take

You put the top character in your dead pile into play under your control. You put the top character in your opponents dead pile into play under their control. Each card will come into play unless there is another copy of that card in the same dead pile. That's it.

Well, technically...

A unique card also cannot enter play if you control but do not own another copy of it, or own but do not control.