No worries on time zones, I'm EST but we have people from all over and you'll find that even if you don't connect in the evenings at exacting times when people get busy you will find we're all fairly active and it still works out because you'll get a reply a few hours later and zip through scenes easily enough :D
Mermaids are lacking right now for sure and easy to jump in with whatever history you wish!! Pirates are just getting their footing back.
I have a small army of people to interact with so no matter what you choose I'd be happy to work with you at getting you going :D