Wow,,, From what I can read here looks like there are a few guys who really have a handle on this Larry,,, Especially in the MA.. I would stay in touch with them,,
As far as the insurance company checks,,, I THINK (JMHO) they low ball it and send part of the payment to the customer then wait for the rest of the bill from the body shop,,, Maybe because if some people get the big check they will just keep it and do nothing and then there are just some insurance companies that are just not that good.
All in all I think you will get some good advice here,,, Try not to raise your blood pressure any more than it already it,,, It will all work out in time,,,,,