Thanks for the answer.
My assumption was that it would work exactly as described by you. However, it does not seem to do so. here's a pastebin of my slave script: http://pastebin.com/Cb3nDK3r
I'll only pull constant values from my controller script. Except the aim offset for multiplying with the velocity vector. That should ot affect the rez position which is outside of the linked prim. I'll checked that. Yet, the issue remains. I'm about to do some tests on a different simulator with another script.
EDIT: It's probably the aimOffset. Checking that now.