We kept our daughter upright in her carseat for sleeping (we put a blanket in it) until she was 8 months. Keeping them upright helps with the reflux and I found my daughter really needed to feel something around her even if swaddling didn't work anymore.
I recommend Elizabeth Pantley's "No Cry Sleep Solution" before doing sleep training, particularly with a fussy baby. However, I think any routine you can provide will help.
On the napping, what helped my daughter was playing music once she had fallen asleep. You could also try white noise. Basically there are different things you do to keep them asleep v. getting them to go to sleep. It's the same with calming them down. There are things that calm them down and then techniques that keep them calm. For instance, if I tried to use music to get my daughter to go to sleep when she's full on screaming, it's not going to work because she can't hear it over the screaming.
