Don't miss Tulume! It's nearly as good as Chichenitza and a heck of a bus ride closer. Chich is almost half day each way, and a lot of walking when you do get there. Tulume is one hour from Cancun. Camera's of course.
My favorite was the water park at Ixcarat. Underground caverns for swimming/snorkeling. (but they make you wear a life vest which makes diving nearly impossible). Also lots of snorkeling (without vests) in the rivers near the bay and in the bay itself. Saw a sea turtle nearly as big across as a man hole cover. My wife actually touched it. Water is very warm. Stayed in our swim suits all day. There is two very nice fine dining restaurants there. (many fast food outlets as well). Lockers available.
Coco Bongo nite club is THE place to go! It's at the north end. Half circus, half nite club. Tremendous and exciting. People on trapeze's swinging out over the crowds, jumbo tron screens, bubbles from ceiling, bar tender's shows, and the usual girl stuff. Bar doesn't even open til 11pm. Goes til 7 am. It's too bad that your wife doesn't enjoy that sort of thing. It's very stimulating and exciting.
Also, if you enjoy fine dining, don't miss The Plantation. It's on the lagoon side of the main drag through Cancun. Dine right out over the water. Wait til dark to go.
I didn't like the city proper, the real city of Cancun. The locals don't seem to like you at all. It's hard to find your way around and if you ask for help, most seem to forget their English. But as you know the tourist's Cancun is out on the peninsula, and that's where most people stay, play, and shop. There the locals are all too willing to help. They fall all over themselves. (tips)
As far as the dolphins go, it's probably fun. We didn't do it because at the time we didn't think it was worth it. (I think it was $100.00 per person for the thirty minutes they give you) But it doesn't cost a dime to watch others ride them, etc. Also, the golf didn't look too good in and around the city. Outlying areas we were told have better golf. The courses right near the hotels looked kinda hokey to me, and appeared designed for people desperate for some kind of golf experience.
I'm very sure you and your wife will enjoy yourself. If you haven't been, be aware that it's very "American". Doesn't resemble older citys like Peurto Vallarta, Matzalan, etc. It's as if you asked American corporations to build a city in Mexico. That's kind of what it felt like to us. Still, it's fun!
Onintwo