If you were happy to change the plug alot and you had it set up right could it be better in the long run do you reckon?
Nope, too much oil would would probably cause too much crankcase pressure, would foul plugs pretty much instanty. You'd be better off at the correct ratio to prolong your engines life
I don't know of anything what'd use 10-1! My mate used 22-1 in his motox bike? Most people run 40-1 I run 33:1.
22:1 in a motocross bike is terrible! Tell him to get some putoline mx7 or mx9 and run 42:1, it will be like riding a different bike!