I am sure glad I picked a skill that translates way back when I went into the military. A lot of what I know I knew before I hit the military, so the experiences dovetailed. Best thing for new military people is get schools, I can at the very least say I are an aviation welder if desparately needing a job.
As far as the QA side, I figure with all the NAVOSH, Hazmat, QA training and such I can write a decent resume to target any position in industrial health and safety. I have a dream aviation job, get hired by the Smithsonian to work at their Dulles re-work facility. I just finished a total of 4 years QA spanning two commands and two levels of maintenance. I'm glad that is done with!
On the do what you want to do side, I have considered race car mechanic, back when I was 15 I was making about $700 a week during the summer. With no bills, somehow I still spent it all. I may stoop to using connections to get a race car job, or work the family race car biz. It is a brutal job market though and you have to know more mechanically than the whole American Chopper cast put together. The travel makes military life look normal. I do it for recreation only right now and it still is quite a commitment in time and travel.
Another option if you still have GI bill or whatever they called it when dinosaurs roamed the earth and you enlisted; is to go get a new skill. If I can financially swing going to Colorado school of Trades, I'll be there.
On the race biz, I ponder it often. The way to make it pay is to sell out front to all the kool-aid drinking street guys, let them buy enough neon and chrome to fund whatever you really want to do. Hire someone competent so you don't have to hear "Doooodz, check this jank out yo!" 80 times a day behind the counter. A wheel dyno will attract Honda Civics for miles around.
