New Boater: "...the real estate agents in most jurisdictions by law represent the seller (even the agent you use to help you find the house, with very few exceptions),"...
Just a small correction. Your quote above is not true anymore. Under today's real estate rules there is Buyers' Agency where the agent is under contract to the Buyer and has a fiduciary responsibilty to protect the Buyers' interest. The days of sub-agency where the agents all represented the Seller are gone.
Just to put the record straight as far as NH is concerned.
Each State has their own laws and regulations governing how a real estate licensee is to treat and work with buyers and sellers.
It is not a uniform situation and can vary widely as to how a State requires licencees to work with buyers and sellers. Sub-Agency does still exist in NH but try and find someone who will offer it due to the potential legal ramifications it presents.
See this link for the actual requirements in NH:
http://www.nh.gov/nhrec/adrule2f.html