It "connects" by a little foyer area exclusive to it and 12260. It's under the outside seating area of the OVC. We did 2 weeks in 12265 and had no issues with noise from above.
If available, fly into Hobby. Although you're not an Uber fan, you'll be dollars ahead using it to/from a hotel in the Webster area. Much cheaper than Galveston.
By our experience Flights By Celebrity doesn't offer this as a choice. Our flights have always included 1 checked bag and seat choice before final payment (thru FBC or the airline).