Overrated? don't be daft.
However, he is not the same 'special' one he was in the first stint at Chelsea. This time he is way more snide and underhanded. He's got to a position where his team HAS to win, simply because he has won in the past and anything else is a slight on his reputation. If he doesn't win, it's someone else's fault.
I think you're right about his coaching methods being limited to a 2yr cycle before players burn out or just want to leave. Win as much as possible then leave and don't care about the state of the team afterwards.
Selling Mata is not about limitations of Mourinho, it's about the limitations of Mata himself in the system. Yeah, player of the year, but Mourinho needs players who will work hard in both halves of the field and not just come alive around the edge of the opposition's box. Man Utd are finding that now. Moyes struggled to find a place for him, putting him out on the left for a bit. He should be a central player but to sacrifice a forward or a holding midfielder for him is a risk. Chelsea have lots of attacking players who can play that role but Mourinho needs to control everything so Mata is expendable.
I find Jose's interviews and comments tedious. Almost as tedious as the media fawning over what a character he is. He's a cynical old bully trying to keep up with better teams by destroying games. Then insulting people or making ridiculous statements that become airbrushed from history or laughed off.