2) Do you see any slow downs only while the menus are open or beyond 
that as well?

3) I've added support for controlling size (actually a one-liner). 
Thanks for pointing out.

Preferences are a different thing, though. It's difficult to get this 
right for everyone unless going for a solution like System 
Preferences.app, which just adds a scroll bar on the right in case 
the window doesn't fit on screen. I'll think about the latter.

Best regards, 
Felix