I can see right off the bat why mom would not be so willing to work with you guys because you are way over stepping your line! I am a step mom to a 9 year old girl my two oldest boys also have a step mom and she try's things like you and I have finally got it wrote into our order she needs to STEP BACK and let dad and myself handle school things (emailing the teacher why would you anyways that is dad's job or mom's job and really every week wow)
If there is NO court order for visitation already then file 50/50 he has a shot at that since he has been there yes she may take son back until court date but after court date then there is nothing she can do. For the child support call a lawyer in your area and just ask if that is a rule they will know and can tell you for free. SOn is now older and things come into play before DID he go to daycare? )mom would get more child support for that) Did she use to pay for health insurence (she would get more for that), does dad get to claim son of taxes? (she would get more C/S for that). If he is aloud to go back for child support he needs to show mom does not pay for health care (so no creidit given to her and C/S lowered right there) if son is no longer in daycare (C/S lowered) show his unemployment they will then base what he can make as aroun $12-13 an hour if he says he can not find a job right now making what he is used to but they will input something in there even if he is not working but at the same time if mom is not working dad can have court input a fake income for her also. But really call a lawyer set up a free counsult if needed and ask these questions or go to the court and see if they have a cheap laywer there that you can see for 30 minutes usally like $30.00- BUT THIS ALL NEEDS TO BE FROM DAD NOT YOU- don't call her, text her, email her she can use that in court and get it in the order to make sure you have no contact with her I did this with my ex's wife she was looney and always trying to text, email me on matters of MY sons

