Skinny, hopefully the knee holds up for sunday.
let me put my sensible coach hat on for a second, and just say if you do find you're slipping into pain territory rather than that "working hard and its uncomfortable" feeling, then consider dropping out. Barring an Olympic final, one race is never important enough to risk a long lay off for.
That said, all being well, I am certain you'll smash the race on Sunday. I really look forward to reading the report.
Sounds like you have in mind a decent strategy. I'd love to say keep the first mile sensible, but I've never managed that in a race myself, so can't really advise anyone else to.
From the training paces I'd set, 7.10 was your original, and then the new one was 7:00-7:05 based from your 10k race., Therefore, you should be able to run 7.10 pacing as your bottom line figure, and quicken as you feel good.
Young Cowboy has it correct, you're certainly in pb form, so remember the hard sessions you've come through pretty comfortably, and race hard and keen on the day.
Drop me your mobile number on a pm, and I'll be in touch on Sunday so I get your result asap 
Edited: 05/10/2012 at 10:04