Hello. I am a solicitor with over 15 years experience. I will try to help you with this.
I am sorry my answer appears not to have been sent I will try again.
You are under no legal obligation to co-operate with the police, If you sign a statement then the prosecution can force you to attend court to give evidence. If you refuse to attend they can issue a witness summons and if you refuse to answer the summons then they can brig you to court in custody. They are unlikely to be able to hide your identity from the defence and if you give evidence your identity will not be disguised.
ok so if i state this then there will hopefully be no further contact with police or P fiscal's dept?
if you say that you do not want to provide a statement that should be the end of it. they can not force you to co-operate.