You will have to find your own sense of comfort. Over the years and children I have found the car seat as my best friend. All newborn have reflux as far as I am concerned. Anytime I have left them laying flat in a crib they have screamed in pain and/or thrown up. It is just too scary for me. I have them in the car seat for the first 6-8 weeks and just move them from room to room with me. The car seat keeps their head elevated and they have less gasto upsets. I think the hustle and bustle of the day helps them sleep better during the night. The noise helps them sleep more soundly too. Trust me, my house is a 3-ring circus.
We actually have the car seat between Daddy and I at night. It is heavy enough that it sets firmly on the bed. The handle swings back to keep it secure. We won't roll on her as if we were "co-sleeping" She is just a "lift your head up and look" to make me feel ok distance.
so in my opinion, baby monitors are ok when they are a little older, not newborns or early infants.
good luck to you.