Lund (and others too) will easily get you one - you just need to tell them what hardware you have installed that is different than stock.
I assumed he wants a new one for the hardware config that came with the pack - FP tunes are conservative so likely one from a good tuner would gain some more hp/tq - modifying existing one - doubt anyone would do that.
They do, although you won't gain that much power unless you go flex-fuel or straight e85. It's up to you whether spending another $500 is worth a handful of hp.
Most tuners will start from scratch. They typically do not like building off another tune which I would totally understand, however, most tuners we deal with like Lund Racing or Palm Beach Dyno, build some of the best tunes on the market for these cars and will make quite a bit more power over the conservative Ford Performance tunes in those kits. If you have any questions about what is offered in the tune world, feel free to shoot me a message anytime. Lethalperformance.com
On a 15-17 NA application different injectors are only needed if running an aftermarket manifold. OEM one does not require injector upgrade.
Exactly. That's why those with the PP2 should probably just stick with it until they do some other major mods like headers and intake manifold and E85 etc.