I have tried air filters but they are just too much hassle in my opinion and not needed unless you are flying off of dirt runways and such.

As for fuel filters, I have one on my pump that keeps debris from going in to the tank. I have used them between the carb and the tank but currently I do not. I use the Sullivan see through filters and during the times that I used them on the carb I never observed them picking up any debris.
I have seen stuff in the one coming from the jug so I keep that one there.

Dbow