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I'm sorry to hear about your son's situation. Technically she can "throw" him out, but he can reënter. That is, the property is the marital property, and until there's a court order that gives one of them the exclusive right to stay there, they both have that right. So if she were to throw him out, he could come back. If she changed the locks, he could get a locksmith to let him back in. She would need a court order to keep him from the residence.
As far as bringing the kids, he could do that, because until there's a court order regarding custody and visitation, either parent has equal rights to the kids. Note that she could then file an action immediately, seek a court order for immediate return of the kids, etc... and that could start the legal process, but there would be nothing illegal about that action.
Hope that clears things up a bit. If you have any other questions, please let me know. If not, and you have not yet, please rate my answer AND press the "submit" button, if applicable. Please note that I don't get any credit for the time and effort that I spent on this answer unless and until you rate it positively (good or better). Thank you, ***** ***** luck to you!