Suggest you focus on having fun on the ship and not worry about the ports, as they are not that great, to me. Hopefully you're not going real soon, as this time of year, it may not be that warm, especially the water. Enjoy your family, and just because there is a line somewhere, doesn't mean you have to join it!! Cruise lines seem to want to disconnect you from the sea these days, but do make time to be outside, maybe aft and actually look at the water, and enjoy the scenery.

Haven't been to Grand Bahama for YEARS, last time I was there, it was just more of a shipping port. Nassau has lots of shopping, and is very crowded, similar to P'burg, and there seem to always be a ton of ships there. Atlantis is amazing to tour, but the prices for that are just astronomical. The private island is a decent beach experience, IF you get to go there. Often they can't go because it is too rough to tender.