My car is falling to bits and I feel powerless :(

[enuff_zed]

I've also noticed that since having my rotors and pads changed, the theres high pitched squeeling coming from the rear wheels at slow speed, a bit like when you leave the handbrake half-cooked. Goes away once I'm over 5-10mph but before that it's quite loud. Any one have an idea what it could be?

Could maybe just that they're slow to bed in and the dust is sticking in the pad until you speed up and clear it.
Have you tried leaving it in gear with the handbrake off, to see if it still does it the next time?
I think I'd leave it for a few miles yet and see if it goes away.
Bear in mind the rear brakes don't get much to do, so won't bed in as quickly as the fronts.