As for the grill lights, they are not part of the MOT, and should only be on when the main beam is on. I'm currently (when I get round to it) changing mine so I can have main beam on without the grill, for rally purposes, so I can drive quiet zones with main beam still.
As for setting, as they come on with main beam, it's where you want, so I have both Kar's and Fakes set above main beam, so I can see I LONG way away

I also have Kar's spots set a tad higher than standard (not much, else they are useless when it actually is foggy, you need to not see the glare in the fog)