1. If you are going camping during the 4th of July you might not even need the rainfly. It is summer and a lot of times I do not even take mine depending on the region. I do not know NC too well

2 & 3: Overall it seems like you need a new tent. By the time you get the seam sealer, get the poles fixed and all that, you will be taking up a lot of time. A small investment now and you will be loving life later and probably will even want to get out more because your equipment is not holding you back.

If you don't want to get a new one, duct tape everything!
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Sleeping Bags