Hi Mrsbalt!
OK, while they may CALL it a boarding time, it is really a terminal arrival time. Your boarding pass number is tied to that time, but boarding usually starts at 11:45 (although it started at 11:30 on our last cruise!)
You can arrive at the terminal with them and will likely be allowed to enter the terminal (if there are large crowds, you can be asked to wait, but that is rare). As to boarding together--technically no, but it is really up to the CM actually doing the boarding. You will each have your own number. Now, if there are 4 of you, there is no way the CM will know whether you are in one or two cabins, so no problem boarding together. If there are 8 of you, the right way for you to board together if for them to hang back until your number is called (you can board any time after your number)
Do note that if you are using
DCL transportation, the terminal arrival time is moot.
Aquaduck times--any time something else big is happening. Do it during a show that you've already seen, during the opposite dinner seating, during the princess gathering...and of course on port days. That said, our longest wait was only about 20 minutes. Rainforest--it was never busy. We like late dinner. Lunch--again, never saw it crowded. Sit down was better than Cabanas. We had a ton of very young kids on our Fantasy cruise, some with parents who were not supervising them--I looked at the fast food outlets and Cabanas, and honestly didn't want to deal with the mess. The ice cream area in particular was constantly being cleaned and still messy. Flo's was OK some of the time.
DO the crazy stuff like midship detective agency, mini golf, etc. even if you don't have kids. It's fun.
When getting out of the aquaduck raft, roll out, then stand up. MUCH easier than trying to stand in the raft.