I have seen the jack-leg work the "Licensed Master Electrician" did on my house. I'll go with me.
As I've said many times, finding a good electrician is difficult. The guy I know and I used to work on jobs together and, if I do install one, I'll work with him.
Normally running gas pipe is not something that is DIY. But I grew up on gas wells and pipelines as it was the family business. I have been working on wellheads since I was 14 or so. So I know what I am doing and am very comfortable doing it. Wouldn't risk my family's safety if I wasn't.
I was never allowed do work as you were, union stopped me from doing anything but electrical work. I wouldn't be comfy with the NG thing, but I'd pay happily to have that done by someone that knows what he's doing.
The permitting process and inspections should cover installation for insurance purposes.