Re starscream:

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Up until "Let's Kill Hitler" I'd have been in the same boat in that I 'd have thought it wasn't that big a thing. Day of the Moon made it seem pretty clear that it was no River who kills the Doctor, it is the space suit itself, and yet Let's Kill Hitler rewrote that to make it River who permanently kills the doctor in Utah i the space suit.

Season 5's spoiler that River kills a good man sounded very clearly to indicate that she kills the doctor, and it would have been great to have a twist on that.

With the various "outs" that the Doctor has. The problem I see is that the build up suggests that no one knows or believes that the doctor survives. Of course this is important for building up suspense for the audience, but in universe it doesn't make sense for everyone to be convinced that the Doctor is really gone forever until really is. The flesh dying in his place wouldn't solve that.

The flesh living in his place and going looking for a way to bring back the Time Lords (because the flesh's timeline doesn't include the Time War) and have them bring the Doctor back though.... now that would make a fun season 7.