I was diagnosed at 22 so I understand about school and wanting to still have a life. I almost didn't graduate on time due to constant hospital stays. While I was sick I couldn't drink alcohol. Not a bit. I would flare really badly, going 30+ times a day and losing so much blood I had to get regular transfusions, and I lost ~30-50 every time I got sick because my flares last 2-3 months.
I had to have my surgeries under emergency circumstances, it doesn't sound like you're nearly as bad off as I was. But there is a general understanding that the ileostomies are hit or miss for people and most people (like 90%-95%) are happy with their Jpouch. (Also i've never heard the term J-bag so you might want to actually say Jpouch so people know what you are referring to outside of the Jpouch community.)
It takes anywhere for 3-12 months for the Jpouch to regulate. the average person will hit their new normal around 6-9 months. I hit mine at 6. I go to the bathroom 6-8 times a day, usually need to pee at the same time, so I'm not going all that much more than your average person. There is almost never any urgency. If I eat something that I shouldn't have I might have urgency, but it is a rare occurrence, not a normal one. I can hold it much better than with UC, and if I'm not standing up I can hold it for up to an hour if need be.
It is important that you approach these surgeries knowing that it will take at least a year to fully bounce back energy-wise as well. It's a big undertaking so patience with your healing process is crucial. if you are relatively healthy you can get the 2 step, but your doc may recommend 3 step.
Once I was out of recovery period I could drink alcohol. I didn't drink much when i was younger, but in the last few years I've become a bit of a beer snob as long as I don't get completely drunk, it's not too bad. BUT everyone is different. Some people cna't handle fizzy drinks, so beer will be out, but you might be able to do wine or liquor. Some people can't do any alcohol at all. It all depends. but if you are considering surgery, you shouldn't table the option just because you might not be able to drink. Just know that it's possible you might not be able to.
Can't help with the nursing questions as I work in publishing. but I do know that there are some nurses either on this board or elsewhere that I've talked to with Jpouchs that still work. Good luck!