Re 1 - AFAIK they deleted it in such haste, than forget to check uploader, and when they reconciled, uploader data was already deleted Or something like that. IRC log in cssu-testing thread contains some funny discussions about it - at the moment of writing, they weren't able to determine uploader.

Re 2 - Ask management, as I may be talking BS, but AIUI, system package = package that exist under same package name in one of so-called Nokia's repos.(freemantle/ssu/mr0 and fremantle/ssu/apps)

Appendix: I think that this situation (and very similar case with marmistrz some time ago) is rather bug/hole of how repos work, than your fault, so fear not. The thing is, that device will install package with higher version number, as long as someone have -devel enabled, and said package is dependency of other package (so, for example, during cssu upgrade, your package was pulled automagically for some, even though they didn't apt-get upgrade).

/Estel