I'm sorry that you have to deal with all of this crap!!
Get out a notebook and start documenting EVERYTHING. It might sound tedious or petty but it is invaluable later on when there is a problem and you try recalling events and who said what and what the circumstances were etc. Unfortunately, you are now at war. And you are up against a ruthless opponent. From what I can gather, your wife is a shoe-in as a JW so they don't need to concentrate on keeping her but they will concentrate on making your children good dubs for the next generation. The fact that, in their eyes, you may be an obstacle to that will only result in the re-doubling of their efforts. And they'll do it all costs.
Do whatever you can to establish visitation with your children. You are their father and you have rights. And set it up with a court order specifying times that are yours. She will then not be able to change things at her whim. Don't let them put something in there about visitation such as "reasonable visitation upon reasonable notice" because then what is "reasonable" will be up to her discretion and from the sounds of it she WILL mess with that. You'll only end up in court again later to change that to keep her from playing games. Work out a schedule that you are able to keep up with and be specific about it "apostateman will have visitation on these days and these hours of the week" etc. And once that has been established, stick to it come hell or high water on your part and keep track of that as well. If there is a party or something in your life you'd like to participate in and it means changing your scheduled visitation with them, don't do it.
You want to establish in reality that you are very involved in their lives. Attend as many of their school functions as you are able. Volunteer for school activities as a "parent supervisor" Call the school and request a copy of everything relating to your children that is sent to their mother. Arrange for your own parent/teacher conferences with your kids' teachers. You don't have to wait for the courts to decide anything for much of that to be put into place and the schools are accustomed to it. But you have to make the request. There isn't anything she can do to stop you from being involved in this way and if she tries to object it will only serve to show her true motives in the end. And it's win-win because you get to spend more time involved in your children's lives. (With all of this I'm assuming that they are enrolled in public school- and not home schooled- if they are- that may be another area to fight in the divorce proceedings)
The other thing I would suggest is to keep a close eye on your children whenever you are with them. How do they seem? Are they happy and well adjusted or do they seem troubled? Your soon-to-be-ex in-laws have, by your own words, stooped to slandering your family on paper, it will not be beneath them then to slander you to your own children. Watch for signs of this and document everything on this as well. Later if there is a need to elicit the assistance of services designed to protect children, your documentation will be invaluable.
Her JW parents have been acting any thing but Christian. I can't believe the levels they have stooped to. I just received my wifes response through the court yesterday, all 82 pages worth. Yes, 82 pages. Her mom and dad both make declarations that are out of this world. I have never seen so many lies told at one time. There is also slander towards my family which they will be sued for.
I sent an email to my wife explaining a couple of various things on Sept. 12th. I also had put in there that the JW cult has been the backbone for many of our problems. With all the research I have done on this organization I came up with only one conclusion: That this is a Satanic Cult. Her and her family have put that email into declarations and say that the JW religion is anything but Satanic. Her mother states that "Most EDUCATED people know that we are not "Satanic"...".
If you have filed for divorce, you may not want to be in contact with your wife through any other means than through your attorney. Too much can be twisted and skewed. And if you establish this even by putting it in writing to her through your attorney, and then stick to it (other than contact regarding the children) then later if she decides to fabricate something, she won't have much credibility with the judge.
I know that this stuff all makes you angry and rightfully so. Ignore what her parents declarations are-I can imagine the judge will.
You will not convince your wife of anything regarding the JW religion. Stop trying. They are lost to it. Focusing on that will only serve to irritate you further and if they were going to agree with you they already would. Hard to let go perhaps but you have bigger fish to fry- protecting your children and ensuring an involved relationship with them. Try to detach from the rest and concentrate on what you need to to to make that happen.
Be prepared for anything. Smear campaigns are already in full swing. Take the high road and don't participate in it. I've got some links for you about that and as soon as I can locate them again, I'll repost.
All the best to you - good luck with all of this.
xenawarrior