Is the hotel the one here?http://maps.google.com/maps?f=q&source= ... 93011&z=12
I couldn't find that one in Cancun.
The only language issue occurred inland when we missed the freeway. Otherwise most people spoke enough english to get by. I'm not sure what the car cost, but for 5 of us it was cheaper than the bus tour. Canadian license was fine. We just looked at a map for directions, I think my dad asked at the rental company. When we got to Chichen Itza there were a few "guides' hanging around, I think he approached us. But he was Mayan and very knowledgeable. It is about a 2 hour drive each way, so if you don't drive much, keep that in mind.
The other fun thing we did was go to Isla Mujeres. You go to the north tip of the Cancun sandspit, then catch a ferry over. You can rent a golf cart to drive around the island, I think we got it for one or 2 hours. All day is probably a bit much. It was also one of the few places we found really awesome Mexican food. There are lots of 5-20 person bars/restaurants up the side streets, go to them. Awesome food.
I didn't have time, but my dad and brother went over to Cozumel which has awesome snorkeling if you are into that.
If you are into nightlife there is one huge club at the north end of the spit. It was pretty cool because it had a big open middle area, then layers around the outside. In the middle they had trapeze acts, and all sorts of action. I think there was a Spider Man performance, with then swinging all over the place. Good entertainment.
Most all inclusive hotels have a buffet or 2, then a few smaller restaurants that you need reservations at. The food is usually much better there, but you need to make reservations, and some items like Lobster often cost a bit that is not included. You will want to go to these restaurants to break up the buffet, but they usually require reservations at the front desk, and they fill up quick, so on your first or second day, be sure to book a few evenings.