Here's my feeling/answers to each of your issues as they were presented.
No hood. I've been carrying/using some sort of beanie on all my hunts now for probably close to 35 years and I've been sleeping with a beanie on my head now (as conditions dictate), for that same length of time. I use a warm hat a LOT when hunting and using it to sleep in is just another reason to have one on hand.
I keep all my stuff (pad, pillow, and quilt), inside a 4 oz. bivy so no need for any straps, etc. I would use the bivy even if I used a traditional bag because I use floorless shelters and like to keep my stuff clean and contained. The bivy also seems to keep things together so as I rarely have an issue with drafts.
My biggest issue with a traditional mummy bag is how confining they are. Regardless of how warm I am, I absolutely hate the feeling of being restricted and the quilt inside a bivy gives me much more wiggle room without binding up when I move around.