My buddies crank seal is on the way out. He had an issue with a high idle on first start after the quad sat for a month or so. The idle would go back to normal once the crank seal was coated with fuel mix. Followup starts did not have this symptom the rest of the weekend.
This last trip out he noticed some oil on the underside of the Magneto cover. Pulled the cover off and several ounces of oil poured out. You can now wiggle the fly wheel as the case bearing pocket is now pretty worn/loose. He has a very low hour engine that is going to be swapped in.
Oil dripping from the exhaust happens on these 500 2-strokes. You might pull your exhaust and clean out the spluge that is all in your exhaust. Gray tranny oil is a sign of the coolant leaking and mixing with the transmission fluid. Base gasket failure, water impeller failing, or clutch cover gasket can be leaking. These are the ways coolant can mix into the trans.
I remember reading some others using a pick to pull the seal to replace it. Not sure if it was a good fix.
Maybe somebody else will chime in with more information.