Realtors have legal obligations to not hide anything from you that you want to know about the home. Realtors have a legal obligation to tell you what they know OR SHOULD HAVE KNOWN. Everybody hates real estate agents when you go to court. When I got my license they told me if you are sued and are going to court the only thing you really need to bring with you is your checkbook.
You’re touching on a real big reason to sell your home through a real estate brokerage. A huge amount of the legal liabilities associated with selling your home will be carried by the brokerage.
Buyers remorse is a real thing, and I’ll wager FSBO sellers are sued a lot more frequently.