i wouldn't have thought so, as the crank and big end probably depend on oil pressure, to keep the friction down,
But if you are thinking of doing this you must have a reason for wanting to do so,
Have you got an oil pressure gauge that is already showing low pressure,?
It's a 2-stroke, logic. There is no pumped oil supply to big ends and mains.
Yes, John999. You can disable the oil pump and premix. Most of the road racers in the '70s,when I did a little club racing, did exactly that. The only real problem is you will have very little oil going into the crankcase on the over-run so there is a danger of seizing when you open the throttle after slowing down. Make sure you are set at a decent tickover and you shouldn't have a problem.
I used to run a Wartburg car which had a 3 cylinder 2 stroke engine, I used to put the oil in the tank prior to filling at the recommended ratio, I ran this car for 13 years with no problem. I think what you have is a seperate tank delivery system where the oil is kept seperate. I would think that if you did away with that and just added it to the fuel like I did it should be ok, the only thing would be to get the correct ratio.
I'd say yes, otherwise you could get extra air into the crankcase through the pump. This would weaken the petrol/air mixture and cause overheating problems. On my old Yamaha it was easily removed and the oil-line plugged to prevent air entry.