Pretty sure the coolant in a 2016 is lifetime (100k + miles) rated. Not sure I would touch it unless it says to do so in your manual. The new stuff is Ph balanced and very advanced. Just use distilled water or Ford pre mixed coolant when you fill the overflow bottle from evaporation loss from time to time.
That long heater hose always worried me in our 99 Brave. It does run through a steel pipe along the frame though. I disconnected the rear heater after the front heater core leaked at 17 years old. Never used the rear heater anyway.
The only other leak we had in 19 years was a cracked overflow bottle. the plastic gets hard and yellow. everything else is Built Ford tough I would say.
Inspect the belt and if its in good shape, drive on. What usually kills the belts is trying to charge a dead battery after the rig sits. You will hear it squeal as the alternator loads up (ask me how I know).
With good coach battery maintenance they seem to last just fine.
On our 2019, the solar charger tops the engine battery after the house batteries are in float mode. Learned a few lessons in the last 15 years driving an older rig.