Welcome to TRT!
on the Keys "beach" thing,,,,hmmm,
there is a mean rumour that the Keys has "beaches"
i can only think of two, maybe more beaches in the all of the Keys.
one's a state park , and i think the "beach" was trucked in,,
where the land meets the ocean, it 's pretty much a rock to water transistion,,,
and on the snorkling thing also, pretty much NO reefs near the shoreline ,as in swimming out to the reefs, mind you there ARE fish along the shore,and the bridges,and in the boat harbors etc.,but not the "reef life" you see in the pics, ya gotta go by boat out a bit,,,
you CAN drink umbrella drinks, look out upon the ocean, or the bay(depends which side you sit on

) and look upon the water,,,,
and the sunsets are FANTASTIC!
don't get me wrong ,I LOVE THE KEYS!(goin down there in Aug.)
just don't want you to expect something that is pretty much not the way you think it is.
in no way am i trying to spoil your fun, just want to set ya straight on a few things. as not to let you down when you get there,,,
it may not sound like it now, but i could be a great spokesperson for the Keys travel board,,,,REALLY!
Go, you will enjoy the heck outa the Keys!