Hi,
blue88 wrote:The other day I wasn't logged in when I added a Joseki and thus noticed that guests had sufficient rights to do so. I don't think that's such a good idea. There should be some kind of history saving the changes and showing who made them. The internet is full of trolls.

I don't have an opinion for this point so far, but I know the Japanese (and maybe some other languages) Wikipedia is also allowing non-registered users to edit the articles. And it's working fine.
blue88 wrote:Ps.: Also it would be nice if you could see all variations you added yourself by browsing through some kind of profile.
You can see the list of your edits by either typing your name in the Activity:Edits page, or clicking the number next to your name in the Find:Users page.
I think it's a nice idea that the profile view has a link to the list.