In situations like this where it's a non-traditional sort of environment, I've often found that it's best to follow the original objective of the job (facilitate the creation of the performance via communication and general organization) rather than to stand on ceremony and insist that the standard rules and job description of the stage manager be observed. It won't be predictable and at times you'll feel terribly out of sorts but any contributions you can make will still be useful. Using your SM skills to see the potential pitfalls coming up next week, the week after, or helping to smooth conflicts between egos will go a long way.
As for the lack of tech rehearsals, though, it sounds like this producer is somewhat oblivious to your dual role as both a facilitator and a performer. People who are very much big-picture-take-charge folks can frequently miss the small details. If this producer is so intense as to want minute control over the schedules, then he/she will also likely be very miffed if cues are missed during a performance. As the communicator/facilitator it falls on you to gently remind the producer that your performance is as critical to the final product as that of the folks onstage. If a blatant "hey, I need rehearsal too" is too gauche for the setting, then perhaps starting to slipstream in questions about where he/she wants cues to happen during rehearsals will be the better solution. (In other words, rather than doing a consolidated tech, get your "blocking" at the same time as the cast.)
