if its regular gas
to put the oil in the lawnmower's crankcase would be fine, so long as it is an appropriate viscosity.
Yes it is possible to do that.
You get engine damage from lack of lubrication
put a bomb in it or you can pour gas all over it and set it on fire
Drain the oil and gas out of the crankcase and put oil back it should be OK
Apparently you didn't crank it up. You are still here. Nothing except it may clean out some old dirty oil. Remove the gas and the oil and discard same. Refill the oil section and refill the gas tank. Don't do that again.
That depends on the model/make of lawnmower, but it will always be on top.
no get new gas
Never put gas in a diesel car. And never put diesel in a gas car. An engine is built to handle one and not the other.
Yes, it may block the carburetor and trash the catalyst.
Into the gas tank.