Just my $0.02:
Starline - It's fine to ask for help on how to handle a situation professionally. I honestly believe this is what you are trying to do, BUT you should find another avenue for this. Ask your husband, mom, dad, friend...someone you confide in.
Don't get me wrong...its good to have outside opinions and I love everyone on this board, BUT when it comes down to it, I am not going to trust someone on the INTERNET with advice with my company.
Its YOUR company (and possibly your husbands or other family members) so ultimately YOU need to make the calls, not people on the internet.
If you have a boarder that you think is "crazy", then have a talk with them. If nothing positive comes from the talk, then its time for them to find another barn. Plain and simple.
Business is business and should be handled accordingly.
It seems to me that YOU are the source of the drama, not the boarders. Its time to grow up a little and have adult conversations with the people that you think are causing problems.