Anyone ever rekey their truck?

Funny, in my mind I read it as airbag too... so that's what I meant. Yeah, not much concern about someone breaking into your vehicle to turn off your airbag.
In fact, I've had a few vehicles that I removed the tabs in the lock tumbler. And they could be started with a screwdriver if you wanted to. Again, what's somebody going to do, break into every car on the street to see if one of them can be started without the key?

 

By rekey, I mean they change the internals of the lock cylinder to work with one key.

As far as how much, that all depends on the locksmith and if they'll need anything additional. Given your tailgate and pass door issues.

 

Have you tried lubricating the lock? Spray a bit of dry teflon lube in there, then spray some on the key, put it in the lock and work it back and forth and left and right to distribute the lube. Don't use anything gummy like grease or oil. Graphite will work, but use it sparingly. A little goes a long way. Paraffin wax also works well. Rub the key on the wax, then put it in the lock and work it for a while. Repeat as necessary. It's amazing what a little lubrication can do for a complex mechanical device like a lock.