Yeah, if you have that kind of commute everyday, I'd be thinking about driving something else besides a truck.... ;)
I drive my 1997 F150 as a DD, but my round trip commute is 36 miles. I go thru about $250/month for gas with it...
If if it was me, I'd consider the F150 you have in mind as a DD only if I was going to be towing a slightly smaller TT than you have listed..
Now, I don't care for that size of TT's to begin with, so it's easy for me to say that.. ;) If I were to want that size TT, I would not even consider an F150 no matter what the 'specs' say... Specs are just specs and really don't mean a thing unless you know what it's like to tow at a vehicles MAX ratings compared to towing with a vehicle that is NOT at it's MAX ratings..
I completely respect Ron's advice, but I've always been one that DOES shop by the GVWR of an RV.... I grew up with a Mother that packed anything and everything to go camping and Dad always had to accommodate that! :) If there is storage space for something, my Mom would find it and FILL IT! ha, ha!
We never found ourselves without anything we didn't eventually use either! Dad would not admit it, but I KNOW he appreciated all the stuff Mom brought!
Anyway, it's all different thinking and different experiences that cause us to do and say what we say, so with that being said....
It's up to YOU to decide what kind of RV you want and what you will pack in it... I have never understood the 'pack light' but have a huge RV that has storage and CCC up the ying yang, yet not be able to use it.... But, again, that's just me and the way my family packed and camped... We did the tent thing and minimal packing and that was fine, but once we got the RV... Well, Mom figured it was time to take what she wanted and be damned otherwise! :)
Okay, enough about me.... It's about YOU and what you want and need.. If towing at MAX ratings is fine for you, great... If having a huge RV and packing LIGHT is fine for you, great.... If the combo you end up with works for you, regardless of it's weights, great.... If not, well, adjust and make it so it's great for you and that's all that matters in the end.. It's YOU that is going to have to tow this thing, so YOU should determine what is going to work for YOU... :)
Good luck and all that matters is what works for YOU! :)
Mitch