I drove my AF865 across North Dakota and Montana this summer on a very windy day. It rocked a bit, but otherwise no problem at all. Hopefully, your 2017 truck is a diesel. I have a 2011 F-250 with a diesel and the hundreds of pounds of extra torque are awesome, especially compared to a gasser. Increasing your speed from 70 to 80mph should kill your mileage.
There is no problem towing a trailer, but emergency stopping with a TC loaded and a trailer might be all but impossible from 80mph. That being said, I could easily bump up to 80-85 to pass a slow camper or texter even fully loaded.
I added upper Stable Loads this year, they are great with one exception. They hit the overload even with the camper off the truck and make it ride like a tank. I'm considering taking mine off and grinding them down a tad so they stay off the spring when the camper is off the truck.
I traveled over 6K miles this summer with zero issues in an SRW truck that was loaded. I passed hundreds of other TC drivers doing the same thing. A dually might be more stable but an SRW truck is not unstable by any means.
A truck camper and a fishing boat/atv trailer are very common in my area.