I have spoken with the team here and they have informed me that while the server continuously makes saves to the database, when a crash occurs, certain actions carried out by the player at this time may not be saved and that is why some players experience the loss of the items and Kamas. This is an issue that we are aware of and we are trying our best to get a solution for it.
Fortunately, our support team are able to look back through the logs of actions carried out at this time and, in most cases, are actually able to refund items or Kamas that went missing after the crash. So I would really recommend creating a support ticket so that you can be reunited with your items floating around in the Stasis!
In response to the topic of costumes, it's important to state that each community has a respective marketing team responsible for releasing costumes. If a community has access to certain costumes, it doesn't mean that another community will have the same access to these costumes. It's ultimately up to the marketing team what costumes get released - and to which community.
I hope that the information I've provided here is insightful, please don't hesitate to get in touch if your questions feel unanswered.