I'm fairly certain I read a blue post at some point regarding the answer to #2. The response was fairly logical, that personal rating change works the same as team rating change; you gain/lose team rating based on your team rating compared to opposing team rating, and you gain/lose personal rating based on your personal rating compared to opposing team rating.
I wish I had a source for this, but the post is likely buried somewhere in the cesspool that is the WoW forums. But this is what I heard, and it seems to confirm option (b) for question 2.
Yes, this does seem to mean that buying/selling teams will continue without too much hardship, but I haven't heard Blizzard caring much beyond giving players netherdrakes who don't deserve them. That is, unless 1 is different from the current way it works.