At first I was having trouble putting my finger on the problems these last few episodes have been showing... but now that I think about it more, the issue isn't that the Producer has difficulty with socializing or expressing his intentions...
...the issue is that these idols don't trust or have faith in the Producer. As the montage in episode 6 shows, and his quick conversation with the oh-so-lovely Chihiro, P-san really busts his ass to get things done for his idols. However they seem to be under the impression he doesn't have their best interests in mind and/or doesn't want to see them become super stars. I'm having trouble understanding why this is so. Sure... he's not expressive... but that shouldn't obscure the amount of work he puts into the project.
There's also this weird idea that they can become superstars over night... which is totally unrealistic. Just because I was the backup singer/dancer for a S+ Rank entertainer, doesn't make me an S+ Rank entertainer. Mio's ego needs to be put in check. She got lucky with that first break. Even if 345 gave her a real stadium concert, she doesn't have her own fan base (outside of her classmates). What she got was exposure to Mika's fan base. The company would have been forced to give tickets away for free, or have her tagged to an S+ Rank idol's performance, to fill the seats. She's supposed to earn her own success... not leech of another's.
Lastly... while I don't think it will happen, this would be the PERFECT opportunity for the anime to stop being centered around the New Generations and move on to the other idols. Yes, eventually Mio would return, but I think they could milk this drama further if Mio was on the sidelines as a not-idol and watch as the rest of the Cinderella Girls rise to fame without her (Shiburin and Shimamu could go solo act for the time being).
If this series had used more of the cast, this would have been a great time to bring Triad Primus into the spotlight... but that's totally not going to happen, until the end of the show. I'm thinking a Triad Primus will be the second season... assuming the anime become successful enough for such a thing.