aevu,
Current FL FJ operator here, and with that in mind, I found your post extremely interesting, as even now your concerns are issues I have with my position in the military.
I never, however, had any doubts at your stage, and didn't even question my commitment to joining, which should be, and clearly is a worry. I was 100% dedicated, and to be honest, I think you will find IOT and subsequently flying training extremely challenging because of this (it's pretty difficult as it is!).
Several years down the line, would have I done anything different? Nope. I've loved it, overall. There are however, significant shortcomings now as life goes on, which is why I'm considering my position.
The flying is the best you will do in pretty much any flying job there is on offer, regardless of where you end up; this is what has kept me in the job thus far.
I would just say nip it in the bud early, your concerns are all warranted, and you will get frustrated. This frustration will be enhanced by the fact you are already aware of it all, and obviously query whether or not the flying is enough to overcome these.
Wrt the boozing element, I don't think that you will necessarily find that an issue. There are plenty of people that do not socialise as much as others, the main reason this occurs is that yes, you can be a bit isolated at times, but also as you've all got a lot in common, and therefore it is easy to hang out. If you don't, then you're not going to fail anything or struggle just because of this. Your UAS experience should tell you deep down your overall thoughts on this.
Don't be afraid to PM me if you have any other specific questions mate.
BB.