Want to File Child Maintenance and Mutual Divorce

I got married in Aug 2008 Mother-in-law was a continuous influence and interference which husband was obsessed with. She called up in our honeymoon too and made such trouble that we didn't speak to each other half the days even there.. Later over the years, husband always tried to show in front of her that he's still close to her and not wife or kid. He used to intentionally not speak to me for days together for no reason. Due to mother-in-law unnecessary disturbances, our conjugal relationship was always in stress and trauma. We had a child and he never had time. If asked, he would say that he can stay at home and give time. I should go to work and provide for him and us and his parents as well. We had a daughter in 2013 and again we were in a state of sleep divorce since 2016 off and on staying or sleeping separately. And completely in different houses from 2018. I am well qualified and started a manpower consultancy of my own, but it isn't doing well. He doesn't take any responsibility so I want to now after so many years - apply for divorce. He didn't agree (without any reason) initially. Now, since I can put him into trouble probably he thinks so, now he is agreeing gradually. My work is not doing good and he earns around 70LPA. I asked for 12 Lacs a year and he is not agreeing, saying he gets monthly salary and would give that monthly. My question: How much should I ask? Should I ask for only child, since I'm qualified (but I can't take full time job for my child) Should I agree with the monthly payment? What if he doesn't pay later? What's the advantage of taking both the maintenance and filing divorce?what's the advantage of filing maintenance but not divorce? How much are actual court charges or what are the real steps is he and I agree on things... Every lawyer here in Delhi is trying to extract Money and cheat. Any good ref?