Adults and children can go on....I am not sure about any height or weight considerations though. MY 4 yr old got a life vest from Community Hall and she had a wonderful time sliding...
As an adult, I always go on the pool slides---they're lots of fun!
Minimum height/weight: none, other than person going down slide needs to be able to go down by himself, and once they make it into the big pool they need to be able to swim out of the way to the side. Life vests are fine though.
Awesome news! I have had my fill of sitting on my deck chair on DCL watching all the kids have fun. My DS will love that I can go down too. He really likes the extra 'help' of the lifevest when he comes out the bottom of the slide so glad to hear those are an option too. Thanks.