FWIW, if a F150 has the 9.75 " rear axle, it is only a leaf spring away from being a HDPP.
To the OP, yes 10klbs is a bit much for regular duty behind a 1/2 ton of any flavor IMO. Although I do it all the time with lower profile loads.
Mileage won't be significantly better towing than with your C. Maybe 1mpg better depending where and how heavy you are on the skinny pedal.
Definately a better dual purpose setup than the C or a Mustang!
Have fun shopping. For a new truck and trailer!
(And take some of the extreme opinions on here with a grain of salt. You can figure out which posts those are...)