If your goal is to help your daughter to grow and mature into a healthy mature woman you will need to put your anger and opinions of your ex-wife completely aside when you are with your daughter.
Children can tell a lot more about how a parent is feeling than most parents realize. If your daughter senses that you and her mommy are always angry at each other this will likely lead to emotional problems for your daughter.
The most important thing you can do is to deal with your ex-wife, the courts, attorneys, etc. without directly involving your daughter at all. When you are with your daughter, keep every single problem with your ex-wife, attorneys, courts, etc. out of the room and out of your mind. Focus entirely on your daughter and how wonderful she is.
This is the only way to prevent your daughter from being effected by such an unhappy and volatile situation.
My first suggestion would be to find a support group of men going through divorce. In a group setting you will likely find that what you are going through (such as feelings of helplessness to protect and care for your daughter as you want to) is not uncommon. People who have already gone through these situations can be some of the most helpful when in comes to learning how to handle situations without self-destructing.
If you cannot find such a group locally, I suggest you start therapy with someone (social worker, nurse practitioner, psychiatrist, psychologist, etc.) so that you have an objective person to listen to you on a regular basis and provide you with feedback and suggestions. There may even be therapy groups that someone in your area could recommend.
When you lose your wife (who is often your best support, at least initially when you get married) you can feel very alone with such overwhelming problems - dealing with your ex-wife, attorneys, the courts, etc.
Eventually, I hope that things will improve within your family to the point that court matters are finished and you and your ex-wife are in better agreement on things. I am not saying you and your ex-wife will ever be on good terms, but at least there should be some settling and calming of the conflicts over time.
This is often the case. Try to look at the current situation as a period of time that you have to survive, after which things will become easier.
Until then, look for a support group. If you cannot find one then call a therapist who has experience working with men going through divorce and child custody issues. Men have very different experiences and feelings about these issues than women do.
In answer to your question, the emotional effect that a divorce has on a child is irreparable. You cannot put a bandaid on an emotional injury. Therefore try to avoid injury. Co-parenting is more difficult when the parents don't get along. Make sure you have visitation schedule from the court and focus on it and follow it. Your wife's anger will always be in the way.
I will leave the custody battle to the legal experts, but I would like to address the parenting issue between you and your daughter. A contested divorce, such as yours, NEVER ends, emotionally. When you think it is over, it is not. Always remember that you are divorcing your wife, not your daughter. You realize that you cannot control someone elses behavior, so your wife will continue on her path of doing and acting as she does, a path of destruction for HERSELF. You need to focus on yourself, your behavior and your little girl, who did not ask for the divorce in the first place! She is wanting strength in comfort, let her find it in you. If you don't have a visitation schedule with your daughter then try to establish one directly with your wife or ask your attorney to get you a temporary visitation schedule for now because it is in your daughter's best interest. Relax, enjoy and have fun when you are with your sweet daughter. Just focus on her and your love for her. Do not ask questions about her mother. Remind her that you are always there if she needs anything. When your visit with her is over, you want her to remember the fun and good things and she will look forward to being with you again. Remember, she is very young. As you move forward, try to ease up on your upset, so that you can focus clearly on what you believe in and whatever it is that you are going after. Anger tends to cloud situations. Stay focused on what you believe in.
I fully understand what you are asking and have to tell you that you can probably answer that question better than anyone. Being deceived and lied to and wondering about the safety of your daughter all the time makes you upset, depressed, anxious with worry and most of all it makes you realize that you cannot control that part of the situation that involves your wife (and your daughter lives with her). BUT you can only help yourself. THAT is all that you can do. You would benefit from a divorce group or private therapy and will make friends that understand what you are going through and you can help and share with each other, but no one can change your emotional feelings but yourself. When you can let go of the things that you can't control, then your emotional state should improve. Unfortunately, you have to rely on the court to help you and they really know nothing about you and your life. I really hope that I've answered your questions. Divorce can be very painful but is sometimes necessary. When children are involved, the pain is worse. Stay strong and emotionally healthy so that YOU can keep the pain of divorce far away from your daughter. Just enjoy her.