As regards point 2.
Keeping hold of McNair, Asoro, Maja, etc would be beneficial to you as they would likely work hard and aren't on crippling wages.
Being left with Khazri, Djilibodji, Oviedo, etc who are likely to throw their toys out of the pram and are draining valuable money from the club could be a false economy. I see little benefit in having them at Sunderland come September the key is getting as much moeny for them as possible. Refusing £6m for Khazri is fine pre-world cup but in August just need to accept the highest offer, whatever it is.