Absolutely yes. If you don't no increase or modification will be made. Every time there is a change in circumstances, you need to file papers with the court to get a new court order. Be prepared, however, to show the court all good faith efforts to find another job,
The report is technical hearsay, Unless the other side will stipulate to the report being received in evidence, you will not be able to offer it without the expert appearing to authenticate the report.
It means that your status has been changed from that of a married person to an unmarried person. You are divorced and free to re-marry if you choose. All other issues of the case still need to be handled.
Absolutely. Her conduct is not acceptable and it certainly isn't healthy for your child.
Talk to a family law attorney in your community for more assistance. If your county has a self help desk at the courthouse, you can get assistance there.
Being pregnant does not preclude you from filing for divorce. It simply means that you are going to have a baby. Talk in person to an attorney in your community to get detailed advice on what you need to do. You can only get a general idea from the web answers. Most family law attorney will talk to you on the phone or at an initial consultation for no charge. Call around and see if you can get an appointment with an attorney who will do that for you. Good luck
Anything you file the court needs to be served on all other parties in your case. In your situation, this is your husband. He can be served by mail and you can't serve it. You need someone who is not related by blood or marriage and who is at least 18 years of age to sign the proof of service by mail (a court form).
You need to make the decision to cut your tie with your husband. You are in danger and need protection. Your husband needs help but you can't help people who don't want help.
I strongly recommend you see an experienced family law attorney in your county to get a family law action started which will include domestic violence restraining orders and orders for financial support. The longer you wait the worse it will get.
The issue is not what the new boyfriend does. What needs to happen is that your son needs to file a paternity action to have him determined to be the father of the child. He can start that now and as soon as the child is born DNA will be taken and tested so the birth certificate can be properly finalized.