there is a point where too much oil is bad.

Gas cools the motor, not oil.  It just lubes it.  So, if you running too much oil you can burn up the motor.  Just like running straight gas will lock up a motor.

Confused yet? 

I change out my plug at the beginning of every season.... just because.  I haven't fouled a plug since i first completely redid my bike.  Over 10 years.