He is keeping the original house, the mobile home & one car. And is offering to give me $5000 and one car worth $2500 for divorc

Since the trailer was put in your name the presumption is that it was a gift to the marriage. The increase in value of his separate home is...

A qualified forensic accountant would be appropriate but this can get very expensive. An initial retainer would be about $5,000.00 to $10,000.00. ...

Do we need to return to mediation to change the living arrangements, or only for a new issue not addressed in the MOU?

I would advise speaking to an attorney here. There are many other issues that come to mind here. For example will you both be living in the same...

I would call the other attorney and see if you could work this out without the need for an attorney. If not obviously you can hire an attorney.

In our divorce settlement, could my husband be required to continue to keep the health insurance for myself & my daughter?

I would enroll with Child Support enforcement in your county they should be able to track him down.

Can text messages be used to hold a landlord accountable for their agreement to allow you to vacate prior to lease expiration?

Any communication from an opposing party can be used against them as a admission by party opponent.