1st of all, by february the rsort will be running on most of it's amenities, so the basics like great beach, pool, bars, most restaurants for great food will be up.
and by experience i can tell you that the staff of an new resort with still some facilities missing will give it all to suit you and your family nice to fill little niches from still missing facilities.
i.e. the resort announced a while ago that the lates finished facilities will be the gym and the Spa buildings, they will run by easter week, but massages aso will be available, they will be provided at the pool area instead the not finished Spa building/facility.
for your teens you will have access to all excursions/activities off the resort than visitors to other resorts have, at your resort all those excursions will be available.
for a family with big kids like yours i would recommend to do a Safari, my personal prefered one is the monster Truck(8 wheeler truck 8x8), also outback safari and bavaro runners get steadily top feedback.
for water based excursions i would recommend the Marinarium(if you want to be with the big crowd, they run 2 story plattforms as boats/catamarans with big party time during the excursion, including snorkeling with nurse sharks and rays) or the Sailcatamaran Patatatu, that's also a 4hrs snorkel excursion, but more family styled because of much smaller groups per excursion.
the first mentioned excursions you can book with your tourep upon arrival, he will have all of them in his tour program, the Patatatu you can see on my website
sailing catamaran excursion sail trip for snorkeling and sunset sail to shipwreck in punta cana dominican republic sailboat
you can also request further info on my mail
mike@mikesmarina.info
of course you can use my e-mail also for additional non snorkeling/fishing questions, there's always a open ear.
happy holidays
Mike