I would like to help you by providing some advice on ui design and usability. I'm quite versed in the GNOME (and to some extent, Apple) user interface design guidelines [1][2], and I have (re)designed tons of desktop application user interfaces. I would like to provide a cleaner look for Bugdar. I will attach an initial mockup of what the "Bug display" page could be made to look like.

[1]: http://library.gnome.org/devel/hig-book/stable/
[2]: http://developer.apple.com/documentation/UserExperience/Conceptual/AppleHIGuidelines/XHIGIntro/XHIGIntro.html

In my humble opinion, a bug report page like this one would be cleaner, take less space, more efficient and easier to use.

I agree completely that the current bug interface needs a lot of work. Your interface mockup is quite nice and I'd love to collaborate with you on some mockup ideas when 2.0 gets to this stage. Keep an eye on the blog for status updates, but I will ping this bug report when the interface work is being done as well.

Yes, in the screenshot there is a "make this bug report private"

This is a feature i would like very much to have. Is this already implemented?

Yes, there is a "Hidden" flag next to the Bug ID field.