Bowes,
Congratulations!
Since no one else has answered your query...Look for alignment of the bed and cab. Many stories of overdoing it led to bent frames. Taking a jump improperly led to bottoming out the rear axle on the bumpstops causing the frame to bend near a nearby frame opening. Trucks with this damage typically have the front of the box riding higher than the rear of the box. RPG, Icon, and others have frame strengthening hydro-pneumatic bump stops to prevent this from happening; SDHQ has frame gussets also.
Early Raptors had problems with driveline "clunk" from a driveshaft to transfer case slip yoke problem. Ford stepped up and issued a TSB to replace the drive shafts in affected trucks.
Power steering problems...the pumps are worked hard in our trucks. There are several companies, RPG, SDHQ, etc that have larger PS reservoirs as well as additional PS fluid coolers.
Lastly the front hub engagement is by way of vacuum, the default is to be engaged. Small vacuum leaks may lead to decreased vacuum which may lead to partial engagement of the front hubs which will destroy the engagement splines quite quickly.
Look for any signs of abuse...crawl under the truck...leaks from the transmission? Differential leaks? Bashed skid plate? Bashed transmission pan? Bent rear shock axle mounts? Loose wires or hoses? Brake fluid leaking? Evidence of frame repair from collision? (overspray, bad welds, body panels misaligned). Has it gone swimming? Evidence of being submerged...pull up the passenger side sill plates and look for silt/mud in the harness wiring.
As stated above the Raptor has thus far been a very good investment with little to no loss of value compared to other pickups. Look carefully, shop around, and don't jump at a deal that seems too good to be true....
Eddie