Steve,
I have been close friends with folks who have immersed themselves in this way of being. For some it turned out (and continues to turn out) very well, for others it was a disaster. The number one factor was the strength of the communication skills of the people involved. I have no worries about your skills, nor Erin's skills - you just have to make sure you find people who are at your frequency and you'll likely be just fine.
Good luck to you.
For anyone who has interest in the basics of polyamory from a philosophical point of view, here is a podcast put together by a philosophy professor in Oregon and a graduate of the same program who has a particular interest in relationship diversity.
Engage: Conversations in Philosophy: What is Polyamory? A New Engage Podcast Series on Relationship Diversity