Most of the guys I've seen coming from regionals have more TT and 3-5K TPIC. Your TPIC is low for any legacy, unless you have something else going for you.

Frankly your volunteer, internal recs, and gold seal pale in significance to the busts, and drug thing. You need some airline accolades, LCA, sim instructor, union jobs, ACP, etc. For the union jobs, constructive things likely safety, CIRP, medical may be better than strike coordinator, etc.

With the black marks, you're probably better off trying for an LCC in the near term and then keep applying to all the top tier. DO NOT fixate on just UAL, that's a bad plan for anyone since any big six job will set you up for life. In your case especially so with the baggage.

I think your real dilemma is whether to try for a LCC now, or stay in the regionals and get some more PIC. With the baggage, I'd probably go for the LCC and get your seniority locked in, that's a good living. Holding out for UA or any top tier might well be fruitless in your case. But you have to make your own call, and age is a factor (sounds like you're not a kid).

Your silver lining is all the retirements, they might get to the point where they cannot be picky about qualified airline professionals with baggage in the distant past. But if it gets to that point you can take advantage of that from an LCC.