MirrorMode/N-Way Multi-Master Replication Clarification

There is another thread "MirrorMode and chaining - are slaves needed?" which
has caused me some confusion about MirrorMode and N-Way Multi-Master
Replication.

Is the difference between MirrorMode and N-Way Multi-Master the number of
nodes?  2 nodes = Mirror Mode, 3+ nodes = Multi-Master?  But both use the
exact same configuration?

If this is the case the documentation does not make this clear at all and
using the MirrorMode directive in N-Way Multi-Master is very confusing.  Why
not "MirrorMode On" OR "MultiMaster On" ??

Is there a way to use two nodes in N-Way Multi-Master replication?