What do you want to be when you grow up? Do that.

You can do whichever option you want. They will all work...you just have to figure out what you value and want in life. I was at 8 years active (helo guy with civilian only FW time) and bailed. May get back in guard or reserves at some point, but waiting until I know I'm at my last airline. An airline will pay me a lot more than the man would have over the next 30 years. You could get your FW time fairly quickly I would think over the next year, use GI bill to help if it's available still to you (or do a sponsored rotary transition program), get on with a regional and hit the majors in a few years, part timing it on the side if you wanted. Do you really want to fly king airs in the mil a couple hundred hours a year? It'll take longer IMO to get a seniority number at a major that way. And, if you want to be a career airline pilot, especially starting later in life than some, date of hire at your career airline should be your primary concern. If you want security from a government job, and airlines are secondary to that, then stay the course. Being single with no kids makes it easier to take a pay cut. I took a huge pay cut going to Mesa, with kids, but my wife has income to offset it. I could live off regional wages these days for a little while, especially as high as they are.

Good to have options as we do now. It's a question no one here can really answer for you though. I was in a similar situation, but younger and with kids. I bailed. If I were in your shoes, I'd keep a part time guard/res job and retirement to help bridge the pay cut and as a safety net while I raced to the regionals and a major as fast as I could. But that's just me.