I know, it is so hard, because you are not only trying to pick a place for the wedding of your dreams, but also a great vacation spot for all your friends and family... so you can't help but think about all their needs...
I am actually thinking pretty seriously about the Riu Palace Mexico now... I know, I know, I change my mind every week, but I just feel like it is a really good combination of the Riu Palace Mexico for those that want to spend a bit more on luxury, and the Riu Yucatan or PLayacar next door for those that want something more affordable...
As for the beach, I am the same, I LOVE swimming in the beach, and plan to do it, and I hear that the beaches can get rough and rocky, but I also hear that people still enjoy it, and get great snorkelling, so I'm not too worried about that...