Mr. Sanchoz is a nice place but they do not have as many water and land toys that Paradise Beach does with the PB $10 wristband. And when you book anything through the ship...it is going to cost you more than just booking it yourself.
As you already know, Cozumel is easily done with a ship tour.
So if you are looking for something that "entertains" the kids as well as having ala carte for the rest of your group...Paradise Beach would be your beach of choice.
Panchos Backyard has always been talked about as a great place to eat.
Coconuts is indeed on the East side....we were just there earlier this month. But it is also kinda "suggestive" for younger children.
And there is no regular taxi service over there....we hired a private driver.
What ever you do...I hope you have a wonderful time and that the newbies fall in love with cruising and Cozumel...