There are surely other people knowing more, but my short comments on your lists would be:
1.) debian.list - looks ok to me
2.) mics.list - looks ok to me, all #'ed, only needed when support says so
3.) passenger.list - (no comment, don't know anything about it)
4.) siduction.list - I would change something:
a) as you have contrib non-free in debian.list, add those also to siduction/fixes
b) I think kde-frameworks should not be used, better change that line to
deb http://packages.siduction.org/kdenext/ unstable main for know and prepare for kdenext being probably deprecated
some day in the future 5.) snapshots.list - I don't know about it, can it interfere with debian, like holding up packages?
6.) ubuntuzilla.list - sounds strange, page looks deprecated, what for is it?
If it's for iceweasel, better have a look at
http://mozilla.debian.net/ 7.) webmin.list - (no comment, don't know anything about it)
8.) x2go.list - (no comment, don't know anything about it)