I don't know about your native worms and actually as to the other question I'm no authority.

You could try adding some of the local worms to your bin but they may not like the environment or might be of little help in producing castings.

Some people would probably say never introduce the non-native life into the area. I've heard that in some locations the introduced varietys of worms have played havoc with native types. Most of these probably escaped around fishing lakes further south than you. I don't know if red wigglers would survive winter in your area away from a big snug compost pile. Unless you sterilize your castings (which kinda defeats the purpose) you are going to accidently release at least some worms as eggs.