Problem 1:
http://bugzilla.zimbra.com/show_bug.cgi?id=3216
Problem 2:
Turn off popup blockers for the zimbra domain.
The app will use popups so if you want to use those features you need to disable your popup blocker. No need to waste time trying to work around this or set it to temporary.
Skipping to the bottom it appears there is a bug with forwarding as an attachment with IE. Please post this to bugzilla with the steps to reproduce (popup blocker off).