I'm baffled by the lack of support for flexible sub-assemblies in motion analysis.  It seems that there's not really a good explanation in the help files describing the behavior of flexible assemblies in motion analysis.  I found a good discussion (https://forum.solidworks.com/message/122329) about this in the forum but it lends itself to a lot of different interpretations.  What are the rules for flexible sub-assemblies?  Can someone please help me by answering the question below?

1.) Do mates in flexible sub-assemblies solve or not?

2.) What happens when I create a rigid group for components in the flexible sub-assembly?

3.) Is friction honored from a mate that exists in the flexible subassembly?