When you had the bike straight up and no oil shown, was the bike on and running? If so, the oil cycles through so you won't see any. When you turn it off, after a few minutes it settles back down and you can see it through the site glass again.
was off obviously:)
If the bike is working as it should you would have no problems leaving it on the stand and revving it until you're blue in the face so if it truly "flooded" by your father reving the bike, there is something not right.
honestly this is the first time in three years that bike stalled.
it was just heating up,temperature was near 40°C/100°F..my dad revved it and bike litterally slowly died.
tried to turn it on a couple of times but nothing, made the procedure to burn the petrol into the cyl and the bike fired up again at frist try.
The only problem that i know was there was lack of oil.
Do you have a PC or Bazzaz unit on the bike? Seems like it's running rich, hence the flooding at idle.
just akra slipon with silencer.
Maybe air filter(stock) dirty?
Bike is running fine right now, just went for a ride and no problem at all...at lest it seems so.
the only thing that i've notice is the exhaust sound, for some reason the noise is more "deep" and the clutch is by far working better.
As far as oil consumption, follow the manual for checking the oil every time. If you stray from EXACTLY what they say you need to do (like say checking it cold, checking it in a rear stand, etc.) you do not have a clear indication if an oil useage pattern. Not saying you can't check the oil in any of the ways I described, but your results will be different checking it different ways. Until you establish a pattern, you are guessing.