I can cut down the extra pipe I don't use. No biggie there, just re flare the end. There wont be any more vibration on the ac than any other camper with gas lines going to the heaters and stove ect.
I looked at the free standing units and I didn't care for that. The UPS man brought my split unit ac this morning. I am now researching if I should make a cage for it (outside part). Or just have a cover for it when not in use. I am thinking a cover. I wished I had a welder so I can run a couple of braces across the front end of the trailer. I was thinking of a diamond plate going over the whole front part of the trailer and then just cut a place for the propane
I am sure I could put in a quick disconnect on the ac line if I wanted to. I will look into it. Might be a good idea in case I ever wanted to take it out without losing the gas. But I know you can turn the out put line off and run the unit for something like 40 sec and the gas goes back to the unit and you can turn it off and remove it if you like but a quick disconnect will work too. Still thinking has I go along..