On Caribbean Princess now. Note that neither Planks nor Steamers appears on the app (no menu, no reservations), so you'll have to visit them or call for reservations.
I'm on Caribbean Princess now and checked out R732 and what's above it. The hallway seems quiet to me (and the OV was open for dinner at the time). Above the cabin is the Steamers casual dining section of the OV, so it's less noisy and busy than the regular OV. Edit: at night, it's open only every other night. People sit there but there's no food served.
Hope this helps!
Comments about healthiness aside, here on Caribbean Princess, there's a salad bar at lunch and dinner in the buffet, along with plenty of cut-up fruit. There's also usually a cheese, olive, and meat spread for a snack.
I've taken the 7:50 am train from MCO three times now and have made three cruises, so yes, a later train is okay. I might even feel comfortable with the next time.
I've received e-mails from Celebrity with a discount code for Brightline, so you might keep a lookout for those.
The buffet is not the hot mess it used to be since passengers have been able to drop carry-on bags when getting on the ship. People don't hog tables while waiting with their bags; they eat and can roam the ship.
I'd never heard of the Corona Cigar Company, but it appears its two locations are in Orlando. I wouldn't stay at the coast to backtrack to one of those. If that's not a must, and depending on the time of year, I'd stay at the coast. (Time of year = water warm enough to swim)