I just met someone today who raised a couple questions in my little brain: Could you worship Sekhmet or Bast OUTSIDE of a Kemetic belief system? Aka, could you worship them without following any of the rules of Kemetism? 

Neo-Wiccans do so, so I don’t see why not. Thing is, in either case, a good foundation from an historical perspective should be warranted when exploring deity/devotee relationships outside of “canon.” I’m not saying it should be mandated, but strongly recommended. It would cause fewer headaches for all involved.

This is really good advice.  Working with a deity from any pantheon should involve research and respect for the god/dess in question, even if you have no interest or association with their mother religion.  In Wicca, a lot of people tend to focus on mythological over religious history quite a bit, which makes it difficult for some people to work reliably with a god/dess, especially those with religions that are alive and well today (like Kemeticism).  Maybe a Wiccan would never feel comfortable reverting their offerings the way we do in Kemeticism, but finding a compromise may be the difference between a lukewarm relationship with Bast and a really fiery bond being established over time!