Compare your #'s to what I tow in my sig. Google my KZ for the #'s. I do not have the BR slide so the pin weight is less.
I am within all numbers and it tows, handles and stops great. A FW works so much better than a long TT.
I have a little more pin weight than what you are looking at but my payload is a little more.
Save some payload by going with a manual slide, if needed or a non-slide if you can. My Superglide weighs 200 lbs whereas a manual slide will be close to 100 lbs. After I bought mine I realized I didn't need a sliding hitch. The pin box and front cap of my FW are designed to not require a sliding hitch.
Where I have my issue is with the waste tanks. When working the numbers I didn't account for the black and gray tanks being forward of the trailer axles. I am over both payload and RAWR while towing with the waste tanks full. I take it low and slow when heading to the dump station when not camping at full hookup campgrounds.
Look where the tanks are on the one you are considering and take that into account.
Can a F150 tow a FW? YES. Can it tow ANY FW? NO. I walked away from a Cougar we liked because the #'s didn't work.