To answer your first question, it was an overnight stay. No big deal.
As for after care, there was none except for regularly scheduled follow-ups with the surgeon. I was a little sore for a day or two, had some diaphram spasms and one of my incisions got infected which took some time heal, but overall it was nothing I wouldn't go through again in a heartbeat. Yes you will be on Vitamins for the rest of your life, but for me the vitamins replaced meds for diabetes and high blood pressure. It's a big step and an important decision which requires preparation and commitment, but there is no way I'd ever want to go back to how I was before the sleeve.