Hello Dawson,
All 15 ships that we've been on have had the muster station location, and instuctions posted either on the back of the cabin door or on the wall right next to it.
The longest muster I've ever experienced was about 40 minutes the shortest about 10 to 15 minutes. Somehow it always feels longer. Take your camera and snap a few of those embarrassing photos of each other.
Yes you have to wear the life jacket. Should you ever really need the thing, you will be very glad that you know how to put it on.
Hot ? Sometimes. It is the Caribbean after all.