[Plugin: BackWPup] Appropriate File Size?

Looking to use this plugin and have scheduled my first job but have a few questions.

1) I want to use dropbox, can I use just dropbox alone? If so, do I need to disable the other destinations?

2) For my dropbox directory, how should that look? Right now I have “Business/Launchpad/Binghamton Marketing/BackWPup/” in that field. Is this correct?

3) My file sizes seem huge, the job is pending and will be run in a few days. The DB is 918.14 kb which looks good but the Files Size is 1.85 GB. Seems impossible that it is so big and also seems like it would take a long time to back up a folder of that size. Any ideas?