So, I haven't been able to find many books that really look into the Necrons in any real detail. Are there any out there?
I also have some questions which might not have definite answers. For starters, can new Necrons be created? It seems like they are focused on finding the old tomb worlds and waking them up or recruiting them (per the little Sautekh box in the BRB), so I would guess that if they can make new ones it's easier to just find old ones. However since they are essentially a species that has been transferred into sexless bodies I would assume they can't reproduce anymore.
I've heard people say that Necrons can't get promoted - that whatever your role is, no matter how good you are at it or at other things, that you'll always be doing that. Is that stated explicitly somewhere, or is that just a common player assumption? After all, Imotekh seems to have moved from Nemesor to Phaeron, so it looks like it's at least possible, if unlikely.