It depends. Some people find it helps while others don't. I record all my essays and listen to them to memorise them. I find that the most important thing is not to do it absolutely perfect, mistakes that you fix up in your mind help by acting as prompts and markers from which to memorise.
Do what works for you-I did both-record my notes as well as review them-it was a good way to familiarise myself with the material-it isn't as tedious as you think it is-because there are often times where you simply feel too tired to read notes-where listening to them comes very handy But make sure you are an aural learner-otherwise this won't be very effective.
depends on your style of learning. If you're a visual person, you would be better off writing your essays, reading over them, or making essay plans. If you're a good audio learner, then recording and listening will definitely be beneficial.
takes a while to record you reading your notes... and even then it wouldn't be as efficient as reading since you talk slower than you read (in your head)
I wouldn't do it but whatever works
I find rote learning the best way to memorise notes
As mentioned above it depends on the person - so I would try it and see if it works. A mate of mine tried this and listened to them whenever he had free time and even when he slept - it didnt work for him so he stopped after a couple of weeks. Who knows though, it may work for you.