That is my worst nightmare! I am so sorry you're going through this. I'm glad you have an attorney. I'm sure he (she?) has advised you to have everything documented. When a man will stoop to those levels to get revenge it just shows what a weasel they are! (((Hugs)))

I didn't think a child could be registered in two different schools at one time? My attorney told me that a child can only be in one school for the school year...my ex started this with my oldest son, he doesn't want the youngest son full time just the older one. Before it even made it to the filing process I put a stop to it because of the school. Now if you and ex lived in the same school district you might have a concern.
He is just trying to shake you IMO. Document that your son is telling you he is alone all the time. Find a way to prove it! I'm not sure you can do much about him being left with babysitters while he goes out though because his attorney will start drilling you about what you do with the child when (or if) you go out. I have an order in place that ex has to call me if he is going to be gone longer than 4 hours. His GF or his family are only allowed to be alone with my children that long then he has to bring them to me.
I hope you have one hell of a lawyer, if you do it will be money well spend. I too get the "This is what you wanted" speech for my ex all the time. My ex filed for custody while he had the kids and it took me 2 weeks to get them back from him. I had to just wait it out because he had the kids physically, but once he did give them to me I took them and he didn't see them for a month until our hearing. If I would have given them back he wouldn't have had to let me see them and that would have killed me. I lucked out, after two weeks he didn't want 50/50 custody, he knew he couldn't handle them 24/7.

Hey one thing that I've really done religiously is document every situation in a little black book! I keep a voice recorder for any crazy telephone conversations and I've kept every email from him for the past year. I had them all printed and sent to my lawyer. Even if you can't prove it, the best thing is to somehow document anything you see, hear, or notice...it's the best way. All our arguments and inconsistencies as parents are normally through text...so that's one advantage I have over him. Plus, I'm ALWAYS attempting to do the right thing. I've sat down with my ex's GF to try and get along with her and work out differences (which I initiated), I've gotten my boys their own cell to call Daddy whenever they want, I make sure we normally do exchanges at a neutral location, I have all of us in counseling for a 3rd party to document his retarded behavior. I'm hoping in the end, it will all work out. I lost my temp custody. What my judge said was if you both wanted the 50/50 why would you want to change it?? I had to prove that the negative impact on the children was because of him and not me...and I couldnt' do it then. All I could prove was that the boys had anger problems and we're being affecting by the divorce but not the one week on one week off. Now, boys have gotten into fights, my 9 y/0's grades have dropped and I have witness to state that he is the aggressive one and not me and his agruments cause a lot of headache for the boys. My advice...when you go to Temp custody...make sure you have enough evidence to prove that he is being unfit and why. My thing is he is emotionally abusing our boys and putting them in the middle of all of this. That a one week on one week off only works with two parents who can communicate effectively and we do not! Document document document!!

I haven't had the custody issue (yet anyway), but I still document religiously as well. I write down when he's supposed to come, when he comes, how long their gone (or he's here), when he shows up to the kids' events, etc. If I know I document when they talk to their dad on the phone, as well. I document when he has initiated it and when the kids have initiated it. I write down what the kids tell me, what I see, and behaviors the kids exhibit. I document phone conversations we have and save e-mails as well. If I made $1/minute on documentation, I wouldn't have to file for bankruptcy. It takes a lot of time, but it's well worth it. And, I KNOW Jerk is no where near organized enough to have documentation of any of this...