Probably the reason why your washer wont drain or spin is because the lid switch is defective. You need to replace it. It is very simple.

The first thing you want to do is check the drain hose and the water pump, because if the hose is coggle the pressure will force the hose to leak.

No. Don't do it it will be a mess. The exterior paint has a very strong smell you don't really noticed but if you applied inside the smell going to be there for a long time. Use interior paint.

Check the drain hose maybe is improperly positioned or deteriorated, also check the drain pump could be coggled and when spins star leaking.

Excessive vibration and noise may be for the following causes: Machine not level, jam nuts missing or loose, noisy transmition, clutch bearings worn, clutch shoes worn, or the motor shaft bent.

Probably the drain pump is cloggled or defective, or the hose is kinked or clogged too. Because if spin normally I do not think the belt is the problem.