In order for the other party to get an injunction, she would have to show more than one act of violence or stalking. If this is all you did, you probably have nothing to worry about. If she does file and a hearing is granted, you should schedule a consultation with an experienced attorney.
I would need more information on the details of this "survivor's benefit" before I can give a full answer. It may be non marital if this was a benefit that accrued before the marriage. Consult with a local family law attorney.
You have a very good chance at getting unsupervised time with your child, as long as you are abiding by your probation conditions and can show you are drug free. You should file a paternity action ASAP.
This is a third degree felony punishable by up to five years in prison. I agree with the previous answer that a prison sentence is highly unlikely, but you need an experienced local criminal defense attorney to make sure your case is handled correctly. It's also a good idea to refrain from talking about the facts of your case any further, except with your attorney.