What would cause my tail lights to go out completely after plugging my standard trailer harness into the u-haul trailer harness by accident on a 1996 Ford Explorer?
It sounds like your power wire matched up with a ground wire on the trailer or vise versa so replace the blown fuse for the marker lights and everything should be good. Check fuses in cab and in engine compartment.
Does using a hard drive from another computer and plugging it into your own computer via sata risky?
You should file an Auto Accident report with your local authorities, this is a standard procedure for any accident whether you are at fault or not. If you have sustained damages or injuries you should also file a loss notice or a claim with the other party's insurer to receive compensation for your loss.