As mentioned, each does something different. You will never need to PPF the entire truck, unless you are going to otherwise beat the crap out of the paint (off-roading, poor washing technique or brush auto washes) and want to keep it nice. I'd at least PPF the front bumper (if painted) and the quarter panel/fender flare in front of the rear wheel (takes a sandblast style beating from front tire debris). Ceramic is a luxury purchase... It makes the paint easier to clean and adds a depth of shine. But if you have the time and desire, you can pay next to nothing for a bottle of high quality ceramic infused paint sealants and apply it yourself every few months after a good hand wash. Same effect, constant fresh coat each time you apply it, minimal cost... I applied TheLastCoat v2 to my truck 6 months ago and it's still working great. Pro ceramics are more durable and consequently more difficult to apply, and have consequences if you don't apply them correctly. And they don't exactly last "5 years" or whatever BS they're touting. They all need maintenance AKA top-ups to fill in molecules where the coating has failed. Unless you're rich and lazy, you're better off spending your time and much fewer dollars using your own stuff as often as you'd like/need to.
Good grief that sounds like a total scam. I'd find a shop that knows what they're talking about. Yes, it's possible some damage can occur if liquid seeps down in a bad spot below the dash and destroys electronics. But there are ways to prevent it which any careful installer should adhere to (for starters, a soak rope that gets shoved between the glass and dash). Windshield tint shouldn't cost any more than $200 (and that's on the high end).
