How are you determining the state of charge on the battery? Using the indicator panel is all but useless. Measuring the actual voltage right at the battery is much better.
"Charges to 100% rapidly." Even with a good converter (not WFCO) mounted close to the battery with heavy cables it'll take 3 hours to go from 50% to 80% charge. All bets are off if you're relying on a WFCO mounted near the rear of the trailer. Again, how are you measuring the charge?
My old Dometic had a switch for the door heater but the new Atwood is hard wired (sigh.)
Do you have a radio with a backlight display that's always on? I put another switch in the line to totally kill any parasitic draw.
Converting to LED's in the lights uses 1/7 the power of a 921 bulb.
I turn the water heater off when we're away and at night.