1. Correct, it is just the name. Nothing more is given as it really is just a way of grouping pictures on your user page. The name can be quite long though so most people who need to put a brief description in with he name.
2. Yes and no, it depends what you mean. If you mean you want to link to a gallery then yes, just view all images in the gallery, set the sort order and then copy the URL of the results page. If you mean elsewhere, then no, it uses either random sorting or a complex muddle of logic which displays images based on who is viewing it.
3. This is normal, it is because the system is tagging each image individually, not assigning tags to the entire gallery. This allows a higher rate of precision and generally avoids single images ending up with unrelated tags.
4. Only by going through one image at a time right now I'm afraid.
Glad you like it, I am continually tweaking it so things will hopefully only improve. Not long now until we hit
40K images too