Hi ya Pixie. You should definitely join this group! Side of the ship won't matter too much because going to Hawaii will be one view, and the opposite on the return portion.
With all our planned group activities you are of course free to participate as much or as little as you please. We do our best to make them very social events, and we encourage everyone, but the decision is yours.
There's a virtual cruise report I wrote during our first Let's Get Lei'd group cruise you can read to get an idea of "the happenings". Though every group we try and do some different things. Here's a link to those stories...
Celebrity Summit Hawaii Cruise, Let's Get "Lei'd"; Cruisemates Cruise Ship Feature Articles