If they did that, they would have created Yet Another Alt Coin (which happens very frequently), and it would have no effect on Bitcoin at all.
Yes, I know that bitcoiners have taken solace in that belief, since the 51% risk became real. Keep believing.
There is no belief involved. What constitutes Bitcoin is defined by the consensus of the miners - period. If a majority of miners were to choose to mine according to a different protocol than what they currently do, that protocol will effectively become Bitcoin. It has nothing to do with what Gavin or the foundation want.
Yes, and that is what I meant: if someone with billions to spare offered to buy 25 million bitcoins, the protocol would be immediately changed to create them, with the full cooperation of miners AND approval of developers.
Again, I think you are just describing a situation where someone creates an artificial demand to create an alt coin. Hell, I will personally create you a Bitcoin clone with a 25 million premine if you want to buy all 25 million right now. I don't know how you will coax miners to continue to mine (i.e. validate) your personal alt coin, though.