I have mine rear facing for my 13 month son. We mostly have it reclined but can not recline to all positions. I think it would sit up to all the positions but this is not necessary because his head would slump forward. He is reclined enough though. I can adjust it whenever I need and it is already belted into the seat. The annoying thing for us is tightening the dang straps!
I'm not sure but my shoulder straps can't be removed. It's one of the only things I really dislike about this seat. The seat was bought for a 1 year old so it didn't make much difference for him but I can see where it would be hard with a little baby.
I don't know because IO bought this for my granddaughter and her parents have a car with the latch system built. I did ask Chicco other questions before I bought this and they were very responsive. The number is 1-877-424-4226 for Chicco. You may want to check with your DMV to see if there are any legal requirements about installation. A lot of parents go to the local fire department and to get help installing car seats safely.