Undercarriage of a truck

Could be moisture in the brake fluid, that does weird things.

collision damage is unlimited.
no one on any forum can inspect your car , only a live hands on
person can do that...
take car to a suspension and alignment shop, and let them look.
or read book on subject. (lots of tools)

DAMAGED RIM OR WHEEL BEARING.

There are any number of commercial protection products available over the counter.. of any auto part store, or online.

In my own humble opinion... Your best protection is regular washing with clean water, and some WD40 on all unpainted surfaces. Any coating you put on will eventually trap moisture and contaminants under it, causing corrosion faster.
Easy way to prevent undercarriage rust is to power wash the entire undercarrage, then spray the entire undercarriage with WD-40 before the onset of winter.

WD-40 displaces water, helping to keep rust under control. Suprisingly, it doesn't come off as easily as you'd think in wet winter driving.
Use use two medium size cans of WD-40 to do all undercarriage, making sure to spray every nook and cranny (but avoiding the brake rotors/pads) until it is saturated.

Believe it or not, one good coating will last all winter--at least enough to prevent rust. Each spring, use a high pressure sprayer to clean the undercarriage and reapply a new coat of WD-40 for the spring/summer/fall months.

it could be plugs ,coil pack,a sensor just have to start checking i would try plugs first then go from there if they dont solve it i think it will..

You need to have your drive shaft checked and quickly - also check the wheels for tightness or best - jack the truck up and check the lug bolts ASAP. This can kill if the wheel is loose and comes off.

About the only thing you could damage as a result of going over a curb resulting in coolant loss would be damage to the bottom of the radiator...This radiator has plastic side tanks which are susceptible to damage...The real damage may be related to any under car crossmembers which may have to be straightend or replaced...Also check for any damage to AC condenser which is located in front of radiator...One simple way to check that is to see if AC is working now provided that it workrd before incident with curb

you need to jack it up and spin 1 tire at a time, use a run out guage on the tires and wheels.a high speed 60 to 65 mph is from wheel balance. low speed is a bent wheel or a bad tire. belt separation

A belt wouldn't cause all those lights to come on, If you were driving through a lot of water like you stated, it might have shorted out the Body Control Module, would recommend taking to a repair shop or the dealer to have this repaired. Hope this helps

The cap should be marked for number 1. The distributor turns clockwise. The firing order is 1-3-4-2.