Hey CJ, my DD was born at 28wks. While in hospital she was fed through nasal gastric tube until I was able to fully breastfed, so cant help on switching from bottle sorry! I did worry about not being able to monitor her intake, but our lactation consultant was great and told me as long as nappies were wet at each change and there wasn't any reddish spots in her nappies (for some reason I keep thinkinging its called uric acid, but Im not sure thats the right name.. it sounds something like that), then she's getting enough. I was feeding 3 hourly to start off with.
Luckily for us she started sleeping through the night about 6 weeks after we bought her home, she would have been 2/3 weeks corrected. She did have days/nights mixed up when we bought her home, but when I would get up to feed her in the night I'd just use a small lamp and not talk to her and put her straight back to bed afterwards which seemed to help, it didnt take her long to sort it out. I also found playing soft music quietly (we've got the pink floyed rockabyes cd, which is great!) helped her to get to sleep sometimes, I think you're right about being used to noise and lights while being in hospital, nurses warned us about it before we left.
Feel free to pm me if you have any other questions