There is a Content aware Fill (which works better and better in every update!)
There is a Content aware Move tool (which cuts a selected fragment and places it into another area of the same layer). What about making a Content aware PASTE to work with different layers?
For fast compositing without precise manual masking. Would be great!
Practically, it's similar to the Content aware Move tool, but should work between different layers.
So, you've already got this functionality inside, just add it to the Paste menu as a new command.