Such affidavits rarely get the case dismissed. In fact, if you say anything that is different than the report, his case will normally be moved to a different prosecutor who only handles family violence cases. Some cases do get dismissed, but it is not as easy as just filing the affidavit.
You do not have to let your son go with your ex. However, it is important that both parties work toward allowing your son the opportunity to be engaged in extra-curricular activities. Unfortunately, these types of activities do not follow a visitation schedule which usually requires the efforts of both parents during their respective times. I know that 3 hours notice is short notice and I would make sure that your ex gives you a schedule of practices and games or talk to the coach directly.
It would be highly unusual for them to dismiss the case - no matter what your wife says to the DA. In fact, if she denies the abuse or changes her story, it is most likely that they will assign a special prosecutor from the family violence unit to prosecute the case. You really need to hire an attorney to review the evidence.
Expunction will not work for a deferred probation. You need to wait two years from the date you complete your probation and then file a Motion for Non-Disclosure. Non-Disclosure will help to shield your record so that most employers will not be able to see the record. However, this will not erase your record completely.
I agree with the other two posts. Probably, you do not have to worry about being revoked at this point if this is the only issue. Probation in Harris County is tough to complete if you still work full time and have a family. Take it very seriously. Don't just do the minimum - go beyond and get whatever you can knocked out as early as possible.
Both parents have equal rights to the children in the absence of a Court order. If you let him visit and take the children and he does not return the children, there is little that you can do to get the children back until you get to Court. You need to hire an attorney and file a SAPCR (Suit Affecting the Parent Child Relationship) along with a TRO (Temporary Restraining Order) to keep the status quo and arrange for visitation, support, etc.
You need to hire an attorney immediately. The fact that she left the children, voluntarily, with you and had infrequent visitations will help your situation. The fact that she ran away with the children will usually upset most Courts (if it was for no significant reason). You need to file for Divorce and also get a Temporary Restraining Order with a hearing. Of course, you do need to have some way of locating her to serve her, but there may be other ways to give her notice of the divorce.
I agree that the normal range will be between $750-$1,500.00. There are attorneys who will handle your case for much less money, but be careful if you go that route. Also, children, property and retirement issues could increase the fees. I would suggest interviewing several attorneys to find one with whom you feel comfortable and that are reasonably priced.
Texas is a community property state. Generally, the property and business that you owned prior to a marraige will be considered separate property. If she has devoted time and/or money to your property and/or business, she may be able to make a claim for reimbursement of that value against your separate property. It can be a real sticky situation. Hire an attorney.