Yes, under those circumstances the business would be a marital asset subject to equitable distribution. You should discuss this with a local attorney and consider hiring an independent evaluator to examine the business.
1. It seems obvious - but hiding in the closet is not the same as infidelity.
2. Understanding the custody situation requires analysis of a number of factors including the age of the children - but if the children are residing with her, your position is going to be a bit more difficult.
3. A restraining order requires more than what you've described - but individuals have been known to stretch the truth in order to obtain them.
4. Video is good, depending upon the circumstances. It can be...
Typically they are retroactive to the date of the petition or first filing - but not always. Add on costs can include health insurance and unreimbursed medical expenses, some educational costs, and daycare. There is no automatic adjustment for the end of spousal support.