[Solace]

Spoiler for Response to your spoiler:

* It looks like the Freezer *supposedly* is a Soul Gem purification facility. Supposedly it's also a place where girls can be de-Puella'd, but I'm not sure that's even possible... and the girls aren't sure either.
* Apparently Kazumi was a Puella WAY before the rest of the Pleiades, and in fact saved them from a group suicide courtesy of a Witch's kiss.

The first one almost makes sense. Remember that Kazumi was able to partially bring back Yuri? From what we know of the Madoka universe, that should be impossible unless you have incredible magical power (on the level of Madoka herself which was supposed to be a unique event), and yet we know that having that kind of power would almost immediately make you a Witch. Perhaps Jyubey's reference to her magic being "destruction" is a misnomer, and he may mean she has control over life and death.

This follows with your second comment. Remember the pile of bodies Kazumi is standing in during the first chapter? Perhaps that was the group suicide referenced here.

Sayaka referenced is also interesting. This is now the second time the Manga has referenced something from Madoka that we the audience would now consider past history. That we know Kyubey is around but keeping himself hidden, and apparently creating Witches is strange enough. We know Jyubey is not quite as clueless about the system as he appears to be based on his rather "evil" face in the panel just after we see him sitting next to Kyubey's shadow. He has plans for the Saints.

More speculah after the chapter is translated.