for the brakes, what i do if a vehicle fails on imbabalce is take the brake shoes out flaten them off and clean them up check the pistons are not seized and that the discs arn't overly worn, put back together with some copper grease on the sliders, usually does the trick
ooh and mot's can be done on a rolling road as long as the rollers are counter rotating and turn at less than 9 mph, ours is a new atl lane and never had a single problem with over 2000 tests