That's PER link, so you can drop it in another folder, change the link, and maybe it refreshes since it's a different link? Can someone from Dropbox confirm this?

Seems like more than enough for simple sites shared with a bunch of people you know. That is about 600 GBs of bandwidth a month, for free.

If you need more bandwidth, you would probably be looking at any of the other innumerable hosting solutions available on the web.