as long as you have a battery, you should be able to flush and pump water thru the toilet.
have you camped in it before? i agree on adding a second battery if you plan to dry camp a lot. or get a generator because using the furnace, lights, water pump, fridge and so on, will drain one battery pretty quickly.
and running your tow vehicle to recharge it, will take hours.
otherwise, you'll have to be very conservative in using battery power.
Dan-Retired California Firefighter/EMT
and Zoe the Wonder Dog(R.I.P.)
2016 PrimeTime TracerAIR 255, pushing a 2014 Ford F150 SCREW XTR 4x4 3.5 Ecoboost w/Max Tow Package