Hi @Phiona
Firstly, we are neither lawyers nor specialised in family law here. Your questions are not related to migration but to family matters. However, I will try to answer your questions as best as possible.
The father currently has the right to spend time with your child. In German this is called ‘Umgangsrecht‘. He is allowed to spend the time how and where he feels is appropriate and also includes what other person your child may spend time with.
It is possible to have the rules around his access rights changed by the family court (Familiengericht). The court can order that the access can only take place at certain times or at certain places. They can also require the access to only take place in the presence of another person (usually a social worker from an organisation that helps families). This is called ‘begleiteter Umgang’. They can also remove the access rights fully as a last resort.
The court looks at what is best for the child and takes various factors into consideration. Here there is a good explanation of the law around access rights (Umgangsrecht) and how to have them changed (in English via online translation):
https://***-stark--familie-info.translate.goog/de/eltern/recht/elternverantwortung-nach-einer-trennung/umgang/?_x_tr_sl=de&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp
The Jugendamt do not take a child into care unless there is a serious threat to the child’s health and well-being. This could be because a parent poses a danger to the child or because a parent is unable to properly care for their child. Doing this is a matter of last resort and is only done in extreme circumstances where there is a danger to the child. From what you have written, I do not see any such circumstance.
I encourage you to speak to the Jugendamt about what has happened. You were not obliged to inform anyone about what has happened previously. You ask whether you have ‘the chance to use it against him’. I cannot assess how a family court would regard allegations of previous aggressive behaviour. For such questions, it is best to speak with someone experienced in this area.
You can also get help and advice from a family advice service ‘Familienberatungsstelle’. If you search online for ‘Familienberatungsstelle’ and the place you live, you will find these organisations. Their help is free, confidential and they usually have someone who speaks English.
If you do wish to go to court and do not have enough money to pay for a lawyer, you can get free legal aid for anything at the family court. This is called ‘Verfahrenskostenhilfe’.
Best,
Éanna