Sometimes it is necessary to remove all connections with the energy represented by a person on completely different frequencies. Not out of disrespect but caution – union as such can result in receiving vibrations that may be dangerous for one’s health.
I see is more as “spiritual environments” that may or may not mix well. Jung used the alchemy metaphor, saying relationships are like chemical interactions. Sometimes they mix well and other times not. But the frequency thing is interesting too. On the whole I agree with you. And the idea is further discussed here:
http://epages.wordpress.com/2009/01/28/conversations-with-a-mystic-part-2-michael-clark-phd-talks-with-teresa-silverthorn/