1- Yes. The baby that sat next to me this past Wed was 4 months old, did not have a seat, was held by her mom and given a bottle. She held the baby the entire trip ( except for that wonderful few minutes when I got to hold her ) ((L))
2- no.
3-Some planes have changing tables in the bathrooms..we wre just on an Alaska Air flight with changing tables in the toilet, the lady next to me with the baby went in there to change her.
I would not have been charmed if she had changed the baby sitting next to me. .
4-get her used to a pacifier now if she does not have one. She has to suck while the plane is taking off and landing, and it does soothe them sometimes just to suck.
How long is the flight? Short flights are best..you will hold her the whole time anyway ..

I vote bulkhead no - like the access to my stuff more than the space.

I always carry extra outfit for each child and a Tshirt that either me or my husband can wear if needed

I would bring paci just in case (I also bought one of those little clippy things so it wouldn't keep dropping to the floor)

Lots of snacks for you is impt as you might not be able to eat when it is time to eat

Also water water water - I always get so thirsty when I am nursing and that might also be a time when it is hard to get someone to bring you water

I have been scolded by flight attendants when I tried to change a tinkle only wet diaper on a 4 month old (meaning it doesn't smell, on a small baby that I could do super fast - with mat down on seats of course). If you can juggle it I would just go to the bathroom - many have changing tables.

Extra plastic grocery bags - Designate one for trash as soon as you get on plane.

Breastfeed without apologies

My guess is you are not travelling to CLE for pure hedonistic pleasure but to likely see family. In this day and age travelling with small ones is more important - our families are spread out, and jobs are global. Be prepared and calm and do what you can to keep your baby calm and comfortable. If other passengers fret over seeing a baby they should carry their own earplugs!

Have fun.