I see.  I am not sure if the Tikali colony thing exists- the attitudisms about the colony I've expressed earlier still apply.  If no diplomatic pact can be made, there may still be spying since that's what the Silent Inperium does.  Telling the Silent Inperium not to spy is like trying to ban inflation.  It just does not work that way.  They'll just see it as a sign their current methods are too obvious and change method.

Be warned with a client colony that the Silent Imperium's recruiting efforts will occur in your sectors for not just the Tikali clients.  The Silent Imperium despite the name behaves more like a very powerful organization than a empire.