Yes the manual states 5w40 or 15w40 for bio blends, depending on temperature.
Yes the manual states 5w40 for severe use.
Yes you should follow the manual during warranty.
With use you described, a 5w40 fits.
Pick one off of the approved list and drive.
After warranty... well, lets say there are a few that believe a 10w30 is just fine, in spite of Ford's recommendation/requirement about bio and towing.
10w30 is the factory fill, and I doubt that any dealer is going to bring the vehicle in right off the delivery truck and switch to another oil for the local area if the fuel is bio laced.
Locally, the dealership uses 10w30, because that's what's on the fill cap, and the manual is ignored. Same at Valvoline Instant OMG.
Now I'm not one to be an outlaw
, I'm a straight up law abidin' citizen, but I would not be a bit surprised if my sump was currently filled with Delo 15w30 and running this fuel in the tank.