Yes. We enter into an attorney client relationship with our clients. Attendant to that are all of our obligations of confidentiality, competence, lack of conflicts, etc. that go with being a lawyer. In some cases we charge our clients up front and refund those fees out of the transaction, in some cases accept the work on the eventual broker's fee.
And not to quibble (but being a lawyer its hard for me to help it), I understand your argument that if the broker's fee comes out of the seller's column on the closing sheet, then that means that the seller is paying. But at least in my line of work, there are lots of examples where one person pays and another person is the client. This happens in contingent cases (if the Defendant pays, then the plaintiff and attorney get paid) in divorce cases (if a parent pays for a child or if one of the two parties has all the money) in criminal cases (parent/friend/relative puts up the money), etc. It is up to the thoughtful, ethical and smart to be able to separate where the fee is coming from the question of who is owed the duty of care. I will readily agree with you, however, that there are many, many, many examples of situations in which this line was not properly drawn and that the power of money can corrupt this thinking.
So in net, if you provide a broker's services, you do so with the same compensation and contractual arrangements as ALL the other brokers in the USA, so you are a "buyer's" broker in spirit only.
So should you participate in a yacht sale to a "customer", will you have your customer sign one of those forms where they acknowledge you are acting as an agent of the seller?
You may have great intentions for the buyer and as much as I LIKE the concept of a buyer's broker, this seems like a lot of mumble-jumbo for an underlying broker-business-as-usual, (which is not a bad thing...as long as everyone understands who is in whose corner...).