Hello and welcome to DR1:classic:
I have stayed at this hotel on numerous occassions and it's a great value for money resort IMO.
As for food at the hotel - there are two a la carte restaurants - one is Italian and the other Brazilian. Both serve very good quality food and you can book as many times as you want however you need to be up early(ish) to book your place in the morning at the buffet.
The Italian is inside - the carbonara is my favourite dish!
The Brazilian is set outside and here they bring round various meats on large skewers straight off the grill, served at your table. There is every meat you can imagine and it's always cooked to perfection. The only gripe I have with the Brazilian is that with it being outside you get many cats joining you wanting a piece of yoru meal! Feed them and you have invited another guest to dinner...therefore it's best not to!
There are a few places within the Playa Dorada complex to eat including Hemingways & Roadways which are American style diners, A fish restaurant (behind Hemmingways - can't remember it's name) and also a chinese restaurant which I am told serves good food. I haven't eaten at the last two before so I can't speak for those however Hemmingways and Roadways are OK places to eat - a little on the steep side but that's what you would expect inside the complex. Oh I almost forgot - there is a Pizza Hut in the plaza too!
Outside the resort there are many nice restaurants along the Malecon - including Aguaseros (mexican) and Barcos (Italian) - both serve nice food and obviously cheaper than what you will pay in Playa Dorada. There is Cafe Cito (another American style restaurant) across from Playa Dorada - head east when you leave the complex and it's on your left hand side - a short walk. There are of course many many more places to eat - what types of food do you like eating? In Sosua you have many more good restaurants.
As for rooms - the Royale section of the hotel tend to be the nicer rooms, hence the price supplement. The main advantage of these rooms is that they come with a fridge and if you are on the ground floor it's stocked every day with Presidente and soft drinks! If you can get one facing the pool area these are nice.
Playa Dorada beach isn't the best on the north coast. Sosua (25 mins away west) is much nicer - clearer water, you can do some snorkelling here too. You also have Cabarete beach (15mins on from Sosua) which is very large and great for watersports. Here you can surf, kitsurf, windsurf etc etc. The beach is lined with bars and places to eat - definitely worth a visit. Go east and you have Costambar beach which tends to be nice and quiet in the week, again clear water like Sosua.
It will be cheaper for you to walk to the plaza to book your tours - there are many tour sellers there competing for your $ and you will get a better deal compared to booking at the hotel. All of the tours you mention and more can be booked there.
There are many threads on here about things to do and see in and around Puerto Plata......use the 'search' function above........and if you have any further questions, ask away
(Here's one I added to the other day
http://www.dr1.com/forums/showthread.php?t=48624)
Oh - one more thing - do go and explore outside of the resort - it isn't until you venture out of those gates that the real dominican can be experienced.
Enjoy your holiday,
Daydream