yes, yr wife can call all concerned for witness including you - ofcourse through court.
you may also call all concerned through court for witness.
while the proceedings going on, you may demand for additional witness, but you have to satisfy the concerned judge.
both the parties will get scope the cross examine to the witness of other parties. therefore donot worry.
prepare your questionieries, based on claim and counter claim of the perties. it is better to prepare it in advance, very carefully and get it typed. discuss yr advocate for it. if he is senior and tell you not to prepare then just obey him.
witness turn hostile means, suppose your wife call some witness, but at the court they support your claim, -then it is a hostile witness, you will be benifited by it.
you complain before the police in advance. you can complain to the judge also. normally it is called trespass - a punishable offence under ipc.
has she getting maintenance or having individual income.