Gosh, I remember back in the days when it meant something to be an Authorized Viper Dealer
Are they E90 experienced?
I would politely ask whoever you work with to do some research on the DLPK and BMWKI before quoting it for you. Explain how the DLPK eliminates most of the wire-by-wire installation, and requires NO firmware updating (if they are a Directed dealer, they are SICK of firmware updating, and this piece doesn't need it).
Also explain that the alarm will only need power, ground, ignition, and a hood pin installed. EVERYTHING else comes through the DLPK IIRC.
Do NOT connect the starter kill relay. Your BMW Immobilizer is fine. In fact, this install may not require ANY of the relays.
By the way, if they do the research on making the clown nose blink for the DEI LED, that would be WAY cool. I haven't spent any time researching that possibility. I know some people are making the clown nose blink in a fake security way.