Aye, I have been told that this thread was in the wrong forum (so I take it that this was a request to move it), but not which one would be the right forum. Since I presume for the content of this thread to be about the planning of some fanfiction, why would this section be wrong?
As for the question, I am generally not into crossing overs and even if none is intended, I personally would prefer any such contacts to remain somewhat more spiritual. If all the dead ones just appeared for a nice chat every now and then with the only difference to the physical presence being that they were a little more transparent, then what would be the big deal about death anyway?