Just had new brakes fitted and there is a 0.5cm strip where the pad isn't touching running around the outer section of the front disc. Is this ok?
Pads probably have a high/low spot on them from wear on the old discs, I personally would of done new pads with new discs
If you ran those on the old discs they probably have uneven wear on the surface. New discs, new pads. Best option.
Moving them won't help. Just transfers the problem. You could give them a bollocking on the road but it depends on how worn the pads are and how bad the low spots are. New discs, new pads. Best option.
The pads only have around 2k miles on them and not particularly hard driving. I know new disc, new pads is the way to go but as they were are pretty much new it should be fine. So should even out over time you think?
It should even out over time, especially if they were only around 2k miles with the old discs, then this "step" is not that high there. You can give it some proper braking a few times as said above to wear them quicker.