At Mahogany Bay, it can take about the same time to walk or ride the Magical Flying Chairs to the beach. Here is an excruciatingly long (to me) video of the ride. There can be frequent stops as people get on or off. Some are better than others and some people aren't as agile and mobile as others.
There are 3 buoys that indicate good snorkeling areas. The easiest one the see is off of the end of the pier in line with the rust bucket. There are two more to the left of that one.
It is normal and the charges will drop off over the next few days or so. I recently had pending charges and with my credit card I can request notification when the status changed. I would receive emails now and then indicating one by one the charges dropped off.
There are porters. There might be (shocking) a line for them. But it would be the shortest line of the day. And they will jump ahead of many passengers to the porter line to get through Immigration. I didn't need a porter, but started considering getting one.