The fuel filter is not a bad idea... but not a necessity. I use a "sintered bronze" filter clunk on my fuel pump pick-up line. I trnd to close off my fuel tank to air when the plane s not in use (a small piece of brass tube to connect the fuel supply line and the muffler pressure line.. keeps air and junk out, and no fuel dripping all over the place.)

I mix up 30 min or 2 hour epoxy and paint exposed wood on any ARF. (and on kits I have built after covering them) The longer cure time epoxy goes on thin and is 100% fuel proof. I occasionally (not always) paint the inside of the fuselage in the fuel tank area with butyrate dope. (2 coats of clear) Butyrate dope is the common type sold at hobby shops for model airplane use. A bit expensive in the 3.5 oz jar... but you don't use a lot of it. (you can get large quantities much cheaper from an airport that has some fabric covered planes... 1 gallon there costs less than 1 quart at the hobby shop)

Alcohol and baby powder and corn meal are things used for cleaning up fuel spills on unprotected wood.