Re: Carb overflowing/leaking. What other maintenance should I do while I'm at it?
Its always a good idea to turn the fuel off when you're not riding. The float and needle valve 'should' keep fuel from flowing, nevertheless even the smallest piece of crud in the needle valve will keep it from closing completely an allow fuel to flow into the bowl. That, and an improperly adjusted float level will also promote fuel flow when you don't want it.
As for preventative maintenance; keep your tires inflated, chains lubricated, check all critical fasteners regularly (don't over tighten them) Brakes, bearings and frame integrity. Use clean containers for mixing your fuel and install a fuel filter upstream of the carburetor. Use common sense and keep your eye on the things you know are important.
These will go a long way in keeping you on the road and running reliably.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"