Interesting / Dangerous brake wear

After buying my mk2 loon a few months back and giving it a good going over, service, new tyres, bit of body work etc, I finally got round to changing the brakes last week. I managed to find myself a set of brembo discs and pads to replace my old squeeky ones. When I came to take my old pads off, the outer pad on each side had around 4/5 mm left on it. Strangely the inner pad on each side had around 12/15 mm left on. Does anybody know why ? and can i do something to avoid ruining my brembo's in this way too ?

I have been driving round on my new discs and pads for around a week and they squeek really loud i dont know if this is simply because they are new ( although thats never happened to any brakes i have changed previously ) or because they are been worn unevenly like the previous set.

Any tips or advice would be appreciated,

thanks Adam.