Even Hillary isn't stupid enough to take Kerry's spot at this point.
Hillary doesn't have to replace Kerry. she , if possible and legal, gets on the ballot as another candidate. She could swing to the middle and siphon off votes from Bush and Kerry. highly unlikely we will see this happen, but it has been a race with some interesting turns already.
Anyone would look good following him.
I don't understand why she would gain from that. When she can sit back for four years, and have a fresh run at that time.
Not if he is alive, but a little thing like that wouldn't stand in her way, would it?