A lot of your questions depend on your local market. I cannot say wether or not your local market will provide enough work for you to make a solid living, nor can I say what you should charge.
I live in Utah so my local market it VERY different from anywhere else. There are lots or Mormon weddings here and because most Mormons choose to get married in the Temple, there are relatively few ceremonies to film. (mostly video montage out side the temple & receptions). And because most of the couples are very young (early 20’s) most don’t have a lot of money to put into a video (unless dad’s loaded)
Because of these reasons I try to focus my work on corporate video.
If you want to do weddings, go check out the next local bridal show and see what others in your area charge, and what exactly they offer.
I hope this helps a bit, like I said every market is going to be a bit different (mine just happens to be a lot different)