This bit is not true. Only with a release clause
With a release clause, if it's met, the buying club doesn't need to deal with the player's club at all.
and even then a club can still push the issue as release clauses are not always legal agreements - more often agreements in principle that would not stand up in court.
Not sure where you get that idea, but in most countries (like say, Spain) release clauses are written into player's contracts by law.
As for egg on the face - it is clearly far worse for them to sell to a PL rival than to let a player go abroad or even walk for free to a rival.
That's up for debate, I'm not sure Arsenal investors and their board would see it that way.
Further, to suggest Wenger would hold onto Sanchez for one more year, when he doesn't want to play for the club, is silly. He takes up a squad place, costs a lot of money each week and will only end up going where he wants at the end of the season anyway.
Selling to us or any other PL club this summer would be like an admission they are not a top English club. Selling abroad would make it far easier for them.
It would make sense for them, but the player can simply refuse to go abroad.
What we do know is this: Sanchez wants to go to Man City. Indeed, perhaps agreements have already been made, as mentioned earlier, between Sanchez and City.
The club can't sell him against his will and are extremely unlikely to piss away £50 million and his wages just to keep him around for one more year. If there's one thing about Arsenal, it's that they don't care about being a top English club when it comes to money. Their transfer record speaks for itself.
On top of all that, if City really want their man they'll pay up for him. Can you see the Arsenal board letting Wenger turn down £60 million? It's just not going to happen.