+1 what most of the other folks already said. Adding to it, it greatly depends on the type of non-flying civilian employment you want. In my case, the FDNY (City of New York actually runs the Mil rules, so other agencies get the same) is absolutely stellar for being a part-time Mil meatbag and continuing my career there while being a gameful participant at the squadron.
Sure, there are lots of pieces of the USERRA law/applications through the FD that aren’t necessarily geared to us non “one weekend a month/two weeks a year” type part-timers, but I haven’t hit any serious speed bumps. Because there are 10k+ firefighters, I’m not even the only Mil pilot/firefighter out there (a small handful, but still).
So, as stated, it will vary greatly what type of job you are talking about, the hit to you not being there while you’re playing pew pew man (an org as big as the FD it’s a blip; some it could be devastating), how your unit/airframe operates (do you deploy for months and have long stretches home/lower duty reqs or very rarely deploy for months but take intermittent trips of days/weeks monthly/quarterly on the reg), and what your participation rate is (usually higher when younger/newer/upgrading and less as you become more experienced or busy on the outside).
Last clarification on USERRA and the 5 year limit: a good portion of your SCHOOL orders (OTS-UPT-FTU-Seasoning pipeline/future upgrades/etc.) DO NOT count toward your 5 year USERRA limit. Some of my orders from these timelines have a line stating they are exempt from the 5 year USERRA limit per U.S.C. 4312 (C)(3). I’ve never actually read that code, but the orders say you’re solid. So, theoretically, you would have longer than 5 years of total protection with a single employer you work for before you started. They don’t all say that and not sure whether they should and that line wasn’t added or just certain school orders are exempt, but it probably specifies in the code listed above. All that said, see above paragraphs/posts whether it actually would play out like that, but the law provides for longer when training is involved.
TL;DR: Non-airline life can be just fine, with the right employer. It’ll depend on a lot of factors, though. Seems like you’ve come around to airline life, which is probably the best move. It’s not for everyone, for sure, and your family/living situation may change/dictate another path, but it’s an absolutely amazing job opportunity presented down the line. It also won’t help having your squadron mates drizzling that cash money/chill life airline honey in your ears all the time. Haha.
Good luck, whatever you choose! The adventure is fun regardless!