Too Rich is, probably, as dangerous as being too lean. However, it generally takes a lot less time to find out you're too lean, and if you're using juice, you can cause the same results you encounter when you're too lean with Nitro. Instant melting of the non ferrous metals in your cylinders . .
On the Oil thing. No matter where you get the oil in the Combustion Chambers, whether it's from bad or hung rings or leaky valve guides or for that matter, a leaking intake or head gasket, if you know basic physics, you understand that oil burns a lot hotter than the fuels we use, if they're anywhere near the correct mix, and if there's enough, (it doesn't take much) your pistons, too, can look like Rabbit's examples . .
And if you use any kind of forced intake, you'll just double your "pleasure" if you get oil in a cylinder . . It's vicious!