I have been to Costa Maya twice. It is a small port but everything is new. It has a nice dock so you don't have to be concerned about tendering, there is a nice shopping area, a nice pool right in the shopping area, a beach nearby, and an outdoor area where a couple of folkloric dances/shows are held each day. The pool, shows. etc are free. A small village is within sight of the dock, but I haven't been there. All the shops, etc. are right at the end of the pier.
Re/ the tours, Carnival has a list of those on their website. As I don't know your likes, dislikes, etc. I may not be able to help you there. The best I remember, water sports are not that great there yet . Tours to Mayan ruins are popular although they are usually long tours. When we were there last fall, we went on an all day tour of some Mayan ruins and enjoyed it. We were there a couple of months ago and spent the day browsing the shops, watched a couple of shows and spent some time on the beach, enjoying that too.
I personally like the port. It's new, developing and likely be very popular one day.
I think you will enjoy the stop there and also think you will enjoy the Inspiration. We sailed it twice, once when it came out in '96 and again a year or so later.
Relax and enjoy.