#2: Yes, we should put this on the navigation menu! I'm not sure if it would best belong under My WikiTree or Find, and be for the user only, or if it should be under the profile menu and be for the profile you're viewing (which could be your own).
#6: We'll get you your own dump if we have to. I want to keep you rolling!
On that, I don't suppose you'd be interested in the full text of profiles, i.e. the bio/sources section? It would be a huge amount of data.
This would open up the possibility of scanning for spelling and grammar errors, though I have no idea how you would do that. With the possibility of bios being in multiple languages and including personal names, it might be impossible. But there might be other things you would think up, like formatting problems.
I would have a separate reason for wanting you to hold a copy of the text of profiles. It would be an extra back-up. And because you're not a WikiTree employee, it would help us guarantee that WikiTree would be free forever. If WikiTree ever disappeared or a successor organization violated the pledge to keep WikiTree free, you could release your copy. (Otherwise you'd have to keep it private, for the same reasons explained in the Permissions and Restrictions section of the database dumps page.)
I can look into how many GB this would be if you want to talk about it further.