Thomo,
There is an article from the Guardian Unlimited online newspaper dating from the start of Foundation Trusts that has a Q&A section that might answer some of your questions.
http://society.guardian.co.uk/nhsplan/story/0,,946032,00.html
On pay it says FTs "will have the ability to pay staff over and above nationally agreed terms and conditions."
Does this imply that they can also pay under if they do not need to attract staff?
Robert