Thank you for all the excellent tips! I experimented with Zoom a bit the other night, and it is amazing. Streaming the game through this, there was only about a 2 to 3 sec lag! I think it will satisfiy my needs perfectly for sharing game experiences with just a few select friends. And since it's really a "live meeting" type client, we can talk through the Zoom app itself, if we can't be on a regular phone call. I may need to experiment a little further to get that working smoothly, but this is definitely providing the foundation I was looking for. It even has very easy integration with XSplit, and it appears to do a great job balancing the needs of security and ease of use. I'm really excited about this. Thank you so much for suggesting it!
Indeed I've heard some great things about Discord. I remember it was mentioned once on stream, too. Definitely noted for future use!