Arguing against PR is a pointless. If the man is the father, he is very likely to get PR. I know of one case (just heard) where the father didn't get PR. Principally, the process of PR should be a "yes" or "no" answer.
Ex can put his own name on the birth cert if he gets a court order.
Guardian appointments have changed slightly In Sept 2008 the guidelines changed to allow any Judge to appoint a guardian if they felt it was nessesary. I guess the increased guardian appointments will be a bit more common. In addition, there is more LIP parties coming to court now, which might offer some explanation about the guardian being used more.
Guardians and DV is an annoying issue with in it's self. If they think you need help, they expect you to take the offer. If you don't, you are "wrong" and unreasonable, even worse, guardians twist the argument into being that if you can't accept good help for you, you can't for your child as well. If you complain about them, you have something wrong with you...like a personality disorder - or something.
The past DV that you want to forget, the GAL wants you to learn to deal with and not forget, even though the GAL represents the child and not you. The GAL just twists things in such a way because you look after the child so you need all this therapy or counseling. While I am not giving advice here, the less guardians (or CAFCASS) know, the better off children and parents are. Obviously if the info is already know, you can't do anything about the problem. Keep in mind, this is my opinion and I am not giving advice.
I personally wouldn't trust a guardian. They have to befriend you, then when you tell them more than what you wanted to, they use the info against you and you are full of regret - and it's to late.
The simple solution is for you to get your own counseling and get proof that you don't need it anymore. Keeping the issue out of court does make a difference.
The talking over you is to try to get you to give more info under pressure, so they can chip away. The thing there is to slow the interrogation right down. Start writing the answer down so you know what you want to say, then answer the next question. Play ignorant till you have written all your points down. By the time you get to the third question, the guardian has to change tactic. Probably try to tell you not to write complete answers.
The alternative is to write the questions down, then write back to the guardian with written answers, that way they get the full answer. You might have to use recorded delivery and confirm that the GAL got your letter.
You might want to find out about what level of access the father wants, so you know what he is actually asking for. The aim is to get to some sort of agreement. Guardians tend to want everyone wanting what they want, regardless of if it's what the child or parents want. Which complicates the problem a bit more. Still the starting point is the father because he is the applicant and he should have an idea of what he wants.
There is no point opposing everything possible - you need to know what he wants, so you know what you are opposing. There might be some things you could agree to.
Sadly saying that the father wasn't interested at the start means that he isn't interested now isn't an argument that the court accepts. The father making an application to court is seen as commitment - whether or not you agree, that's what a Judge would see. A Judge can only make an order for "no contact" if there is clear evidence that the father will hurt the child and the child is in danger. You are better off looking for a way to make things work. The working might not be ideal but toloratable. To make matters worse, some fathers don't bother after they get a contact order. It might not be the same with your ex.
Keep in mind that there are a few good CAFCASS workers. Sadly the good ones who work in an open, clear and transparent way are so few.