As the air coming out of a rotor is of higher pressure than that going in
Oooohh are you sure about that statement??? It may be going faster but higher pressure??? I'm sure Mr Lappos will have something to say about theories of lift production on that one
The converse of having the puller TR 'downwash' impinge on the tail pylon is that with a pusher, the air has to come around the pylon which can lead to blanking and require a bigger TR to give the same thrust.
The direction of rotation can be changed as it was on the Lynx from Mk1 to Mk 7 - the Mk1 had the forward blade moving down through the MR downwash and had poor TR control as a result. The Mk 7/8/9 has the forward blade coming up and is very effective.