I agree with everyone else. Get a good warrantee and enjoy the truck. When I got my Gen 1 (2011), I had 2 problems that were fixed either through warrantee (leaky cab from a bent tube on install) or a TSB (axle chirp). Aside from an annoying temperature control gauge knocking, everything else has been minute and easy to fix. I posted here about a ticking under the hood before, fixed that with an oil change and an oil treatment additive. The truck was at 100k, so it was expected. From what I've seen on this forum, Ford has been pretty spot on about taking care of folks that buy their vehicles, at least this truck in particular.
As far as my track record with Fords, I've had an 07 F150 XLT that never had an issue. Sold it at 25k miles. Had a '04 Focus that didn't run for a year because I let it sit, started right up after a charge and was perfectly reliable before and after that. First truck in high school was an '88 Bronco. Again, aside from small maintenance issues, like a small radiator leak, it was reliable for about 200k miles until my dad rebuilt the motor from some worn pistons, I think. It's his now and with his meticulous upkeep, he keeps that truck and his '77 F150 running reliably. Both as daily drivers. My buddy's Gen 1 is at 130k and he's never had any issues at all. Same year as mine.
Point being, these trucks will last decades if taken care of right and again, Ford will take care of you too. For sure do what you do and do your pre-purchase checks and find a good warrantee for your own peace of mind. I did. But don't fret, you'll be happy with the truck.