Legal Question in Real Estate Law in California

I believe, without knowing, that the answers are "yes" and "yes." Revealing the identity of the bidder would be going a bit afar, but I can think of no good reason why the current high bid for a property should not be revealed to another prospective bidder/buyer. Remember, there are both sealed-bid auctions and outcry-type auctions, each with its own rules. Sale of real estate is more akin to the latter.

There is nothing illegal about it at all. In many communities it is considered unethical to do this, and agents/brokers who do will find themselves ostracized, will have trouble getting listings or getting their listings shown, etc. But there is nothing illegal about it. Now if the agent represented the first buyer and the second buyer, there probably would be, but if only the seller and one buyer, there is no legal violation.