question about installing software from sid repos
 

Have you noticed that many things available in the Sid repositories will, if you try to install them, want to remove a huge amount of software (sometimes enough to destroy your system) and/or have an unusually large number of dependencies? I don't need to be told to leave such software alone, or to not use the Sid repos unnecessarily, but am I right in guessing that these items just haven't been fully prepared yet? I'm surprised they're available in any repository. Why would anyone download software that will promptly shred the operating system?

The code name for Debian's development distribution is "sid", aliased to "unstable". Most of the development work that is done in Debian, is uploaded to this distribution. This distribution will never get released; instead, packages from it will propagate into testing and then into a real release.

"sid" is subject to massive changes and in-place library updates. This can result in a very "unstable" system which contains packages that cannot be installed due to missing libraries, dependencies that cannot be fulfilled etc. Use it at your own risk!

http://www.debian.org/releases/unstable/

If you want to run Sid, you run everything from Sid. Else you stay away, and this is by design.