Hello, I am a solicitor with 20 years experience. I will try to help you with this.
It is not unusual to be rebailed by the police repeatedly. This is usually though to enable the police to obtain further evidence or carry out further investigations. When the file has been sent to the CPS there would normally only be one more bail unless they advise the police to carry out further work.
Unless there are conditions on your bail that are accusing you inconvenience the best approach may be to just say nothing and keep returning to the bail appointments. It may be that the CPS have lost your file (this is not unheard of) and the longer things are left to drift the less likely it is that a prosecution will follow. If you start complaining etc. you may prompt the police or the CPS to take action that leads to you being charged.
They might r-interview but might not. If they had sufficient evidence to charge they would probably just charge.
They should do that but they might re-interview. If they do you need a solicitor there.