My litte one turned 4 months today and we are going through something similar. Her naps are just 30 minutes long too, but thats another story!
Between 6:30 and 7 PM is a good time to go to sleep. You should expect 1-2 feedings a night. I thought we were doing great until about 5 days ago she's been waking 3 times a night and I'm starting to think that I need to see if she'll just go back to sleep on her own (crying or not). I've been reading "Healthy sleep habits, Happy Child" I checked out at the library and it's been really helpful. Based on actual research from a doctor, not opinions from a mom who has a few kids.
I am also nursing and it seems she prefers eating for about 5 minutes every 2 hours. I'd like it to be longer but feel like I need to feed her if she's hungry! Keep track of how much they weigh and if it's on track at your well-child visits & if hes not a big big baby then don't worry about it!
For bedtime routines, I'm just don't feel like giving her a bath at night everyday so I don't; lots do and that works. I incorporate a short book & a couple songs. Feeding & changing can be part of it. I don't think it matters except just pick a few things you like and keep it calm & consistent.
No other food for baby until 4-6 months. My first daughter threw up everytime I gave her rice cereal, which I started on the day she turned 4 months, so this time I'm waiting a bit longer.
BTW someone said that formula takes longer to digest because its cows milk! No it's not!! It does take longer because it makes larger lumps in the stomach, but thats not a reason to switch to formula.
Good luck!