Any reason I couldn't T the black pipe with a black pipe T , under the trailer, And run the black pipe in the trailer off of the black pipe T. Thus decreasing the amount of copper I am using. Also not having any copper exposed to the road will help keep the line from getting damaged. Am I off on this thinking?
Chris,
As Bob pointed out, you don't have to use any copper at all.
Though copper doesn't generally split unless it has water in it that freezes, it is easy to kink.
Copper can get damaged under a trailer, but it is uncommon.
Copper leads are very handy if you need to snake the gas line around multiple bends.
If you have a straight shot up, there is no reason you can't run black pipe up.
Installing a shut off at the end of each such run is handy, and doesn't cost much. Using a gas rated flex pipe from there to the appliance will complete the run.
Be sure to secure the black pipe well.
Rob
Waiting for "someday" will leave you on your deathbed wondering why you didn't just rearrange your priorities and enjoy the time you had, instead of waiting for a "better" time to come along...