If wanting the cheers package I would book one kid with one adult
Kids will be in CLubs- 12-14 15-17 depends on how close his birthday is they may move him up also depends on the number of teens. Your oldest will be able to move down in the clubs but not really fair to him to do that. We took 2 teens in August and they were in separate clubs- both did well with meeting new friends.
Its important- VERY importatnt they go to the first night orientation usually about 8:30 and stay for ice breakers. this is where they meet the kids
xbox in the clubs are rarely used - its there but only for group activities more stuff going on and happening then video games
the balcony divider does not open on connecting cabins. (silly isnt it) but the divider would block a cabin door so it can not be opened. The connecting door is at the foot of the bed
at 16 and younger your kids can not drink in any port
dress code in dining room is khaki pants for formal night. other nights shorts but not cut offs or gym/basketball shorts
For us- dinner as a family was madatory. as the same as ports. we did the ports together.
Considering they never been- how do they know they will not like it. Stuff is closed on the ship while in port-- no stores no casinos. very few activities-- maybe trivia happening. But yes they can stay on the ship without a parent. But will not be able to get off unless a parent is with them should they decide later to venture out (hope that still applies today