As an ex MOT tester can i give you some advice.First your current MOT station are not trying to be difficult they are only thinking of your and other road users safety and the regulation issues you are experiensing often happen due to the amount of tester discretion actually allowed within the regulations and the experience of the tester. I would put your bikes issues in this order.
Point 1,Brake light, some would pass your bike and some wouldnt. I personally would fail your bike for no brake light.It is an easy virtually invisable modification to fit one with independant wiring AND it could save your life!! Modern road users expect other vehicals to have brake lights so fit one! I fit them to my pre war Triumphs and would not ride without one.I would also like to point out the obvious should you decide to have your garage do a daylight MOT by removing the lights,you would actually invalidate that MOT if you refitted them and if you drove after dusk you could be prosecuted for no MOT as it is only valid in daylight.
Point 2.The front number plate was a legal requirement and was then made NOT a legal requirement due to road injuries.However it was never made illigal and it is quite permissable to have one.
Point 3, This may upset you furthur but if your oil leak is a bad one i would fail your bike for that!Regulations changed recently naming oil leaks as a valid failure on safety grounds with the tester having discretion on the seriousness pf the leak.As your bike is a Two stroke unless you are talking of unburnt premix leaking from the exhaust i can only presume you have a gearbox oil leak which is a serious thing as if it runs out of oil and seizes the gearbox, your back wheel locks and unless you are very lucky you fall off!
I think you are looking at your bikes MOT from the wrong perspective.It is not a test to cheat on or to find a way around it is a safety check on a vehical you drive at a speed that if it fails would potentially cause an accident.