I wouldn't mind seeing them go, but P&P worked well as a team with Ayu and developed a strong relationship, which is arguably more important than their singing abilities/voices. Also, P&P are not trying to take Ayu's spotlight, Ayu's wants them and the rest of the crew to have their spotlight as well.
I also wouldn't mind seeing to dancers go too. I'm not impress by them and their dancing are not very well syncronized with the music (they could use the same moves with different songs), but there are exceptions.
As for the band members, yeah they can go too. It's not hard to find talented musicians, there are many of them lying around somewhere.
I also wouldn't mind seeing Ayu go too. There are plenty of other better singers.
In fact, change everyone, even the audience, there are better audiences out there. Avex should be taken over as well.