I change my oil once about mid-week, because it's so ridiculously easy to do, and sometimes by then I've run them long enough that they're due anyway. I bring a laundry detergent jug to dump the old oil into.
The air filters get cleaned a lot. I bring spares.
I do use a generic inline fuel filter. It just seems like a good idea and they're super cheap so why not.
Kingtom, I'm mostly running my camper's stuff - A/C, a Rainbow vacuum to filter playa dust from the air inside, a microwave, etc. and I run an air compressor, welder, big lights, battery chargers, and whatever people around me plug into the extension cords I usually string out for them. It usually requires two of them, but if I were you I'd definitely bring your Honda and just run on it whenever you can for exactly the reasons you listed.
When you run a pair of Hondas, you can shut one down when your load is really light, but I've found that if you have enough electric draw going to make one Honda throttle itself up, it's actually quieter to run both just because they'll only be idling.