Sound needs Com for emergencies. Not just dead mics, but if a Cue series crashes and burns and you need to slip into a hold, they have to know it. Also if you start running into sound issues backstage (monitor issues for instance) they need to be able to be in the Com loop.
Lose the Conductor. Cue Lights or an established protocol for Overtures and Entre Acts work fine. OR throw an ASM or Floor Manager into the pit to give the cues, and then they bug out for the rest of the act.
I'd say keep the spots as well. If you have a great Op that you can depend, on fine, but in general you need that part of the Com loop for dependability for cueing.
-Chris
TD, Greenville Performing Arts Center