Hi,
   Good luck with getting started.
  As for what to charge, there is not a clear cut answer.  We charge a variety of different ways depending on the service we are providing.  In some cases we charge a percentage, in others we charge a per claim.  If we are providing a full service it is usually a percentage, but if we are just needed to submit the claim, with no follow up, etc, then we do a per claim.  We also have a couple other methods, such as a flat monthly fee.  You have to be careful, some states have laws on charging percentages, so you have to alter your wording a little.
As for the LLC, that is not my department.  Alice will be answering you on that tomorrow.
Thanks
Michele