I'd like some of the girls to get mandatory dance training. They've been at it for a long time, and they're professionals, and they'll pull of the choreography they're given, but they won't have the opportunity to really push their own limits as long as the weak links aren't able to make that jump. The choreographers will straight up not push them because they know Maasa and Risako might not perform it as sharply, or Yurina might not hit it as elegantly. I love the choreography they get, and it isn't bad most of the time, but they're only comfortable in it. The girls can also use some vocal training to polish some rough edges. There is no reason why Maasa should be butchering Semi in fan events.
It's also possible that the girls as a group feel that management is treating them as second tier. That's gotta be annoying. There must be a reason why Miyabi will push it in Buono! and Aa! and DIY! (look at those exclamation points.. talk about pushing it.. haha), but then lay back a bit in Berryz. There may be so much misdirection just in the management and staffing that the girls don't know where they're going or where they'll be a year from now. Are they just waiting and dreading the day that Tsunku walks into the room and tells them that they're disbanded? When they're celebrating "10 Years!" on their 9 year anniversary, it's gotta instill fear that they might not be around next year.
EDIT: Is Berryz the only current H!P group without punctuation? Conspiracy! Talk about misdirection. They don't know if they're a statement, an exclamation, a question, a temperature or a fraction.