1) Works on my server and I dont see the text you described. Which language do you use in ispconfig? The info text was there in one of the pre releases, so I guess your server is not updated to the final yet.
2) The admin module does not show up in the list of available modules. It whowed up in one of the pre releases, so your system does not seem to be using the files from final.
3) Login as user when clicking on the icon in the admin list works fine here.
4 + 5) See Falkos post.
To fix the issues on your server, redor the update by using the manual update instructions from the release notes and switch to the default theme or contact the developer of your theme and ask him for a updated version for ispconfig 3.0.5.