All he owed us as manager was to see his contract out and delivering satisfactory performance in the league. Why would he sign a new contract if he knew there was a chance he was leaving? As he has stated, he wasn't sure he wanted to stay and if an offer like United came in, he'd be off. There's absolutely nothing wrong with that.
As for knowing he was leaving and running his contract down, when he accepted the offer (no one can act like they have the slightest clue when that was) we all saw how much everything in the media was about Moyes in those last two games, if that had gone on for weeks or months it may have hurt the team's form. I'm sure he didn't want any distractions for the players and staff and so said "I'll leave it until the end of the season." It's clear what he was doing. He was honouring his contract and delivering the best performance he could as that is what he owed us. And he did, we finished the season strongly.
I don't remember many quotes like this and I doubt they're as bad as you're making out. In any case, he'd be entirely correct. We were utter, utter sh*te when he took over.
I'm pretty sure the financial side of transfer negotiations is not one that managers get particularly involved in. It's not what they're paid to do. He may well think Baines is valued much higher than £12m, but United have to get the best deal they can. They wouldn't go straight in at Moyes' evaluation. No way. Moyes is on the buyer's side anyway now, so his valuation has nothing to do with anything. All that matters is how much Everton value him at. If Bill fancies cashing in at less than Moyes' valuation now he's gone, United would be fools not to go lower. It's the same principle as him not signing a new contract. He could be screwing United out of millions if he helped little old Everton out with a massive bid.