The 'MK' thing in 7 and 8 is dangerously close to the MK Dons logo. Working in Milton Keynes I've seen a lot of 'MK' things which really don't work, so it'd be good to see someone do something good with it.
I like the little device in 9. I agree with the other guy, they look slick and all, not really my thing though. I quite like the font in 8. If the device in 5 was simplified a little I think it could work quite well.