Lots of good questions.
1. All of settings are what I use at the dunes. Don't leave the transmission in drive. You'll need to manually shift it.
2. 20psi is what I run at the dunes. No issues with popped beads in two years. You could probably go to 15psi in really soft sand. Just keep the speed down while turning sharp. Manual shifting starting in first gear and keeping the rpm's up will get the tires spinning. I bounce my rev limiter all the time!
3. If you're not on mid perch I'd only go 12" to 18" with a flat landing. It's going to come down nose heavy. BAM there goes the stock skid plate! It's a 6000lb truck. With a roller style jump, two feet is ok.
4. Whoops. It really depends on the spacing and height. I used to roll all of the 18" to 24" whoops until I grew a pair and just said what the hell. I now blast those same whoops at 40 to 50 mph. My buddies in their RZR's can't believe that I hang with them. At those speeds the stock shocks get warm quick and pack out. It's just like riding a dirt bike or quad in the whoops. You're skimming the tops of them.
5. If you're on flat sand and hit a dune face with to much speed you'll damage your skid plate and maybe front OEM bumper. Plan on sacrificing the skid plate just learning how fast is to fast.
FORD RAPTORS - YouTube
PM me if you want and I'll share everything I know with you. I've taken many PNW Raptor owners to the dunes in the last two years and we've all had a blast!