D.C.
I have a similar morning routine with my son. So I got good at nursing while lying down in bed. So I would lay on my side, nurse the baby, and still reach over with my other hand to rub my son's back. I kept the morning routine as much as possible and we all kind-of cuddled together, which was really nice.
Sleep is a lot harder with two. Make sure you nap any chance you get. I admit I actually kept my older child in preschool while I was home on maternity leave so that I could sleep when the baby slept. If you need to, find a neighborhood teen to be a mother's help and take the toddler for an hour every now and then when you know the baby is going to nap so that you can nap too.
As for the last issue - for me it was a non-issue. My older child NEVER woke up because of the baby crying. He slept through it all, and their bedrooms are right next to each other.
Congrat, and good luck!