I have a Honda 3000 watt RV generator and it has a fuel shut off and a float bowl drain. So if you shut off the fuel shut off and drain the bowl the only place there is fuel is in the tank and the lines to the shut-off.
I have added air bags to my truck and it's great. Better ride, better handling. Great investment. I don't have an onboard air supply. I'm pulling a 12,000 lb 5th Wheel with a GMC 2500HD Duramax
There are natural gas vehicles around and also propane, I don't think I would worry about hydrogen exploding any more that natural gas or propane or even gasoline.
Watched your video, you did a great repair. I looked at my Jayco Eagle 5th Wheel which is a 2006 model and was worried on what I might find but it's like new. It is constructed similarly to your 5th Wheel. Just wondering if there was another reason that this section failed?