Approximately 9% is the most common. 3% to your listing agent, 3% to buyer's agent, 3% to county, title, etc.

Real estate commissions are negotiable. The rest of it is basically hard costs.

Zero.
Modern escrow accounting is very good, and the money is pretty much always where it's supposed to be.

I tell my clients that the taxes and other service fees (title, escrow, county recording, etc.) associated with selling a home will run about 3%, depending on your county excise tax rate. It's usually pretty close, within a couple hundred dollars, and most always on the high side. The Realtor commission rate is something you can add to that.

According to surveys from the National Association of Realtors, sellers using the assistance of a Realtor in selling their home typically net a higher percentage of profit than for sale by owners, even with paying the commission, since buyers of FSBO's tend to negotiate a seller to a sale price below that which is market value, and below the cost added of using a real estate professional. Their reasoning is that since the seller isn't paying a commission fee, they should gain that profit in a lower sale price. So, in actuality, sellers don't typically lose when listing their home with a Realtor.

Wayne Langford, Realtor
Windermere Real Estate/Tri-Cities
Kennewick-Pasco-Richland, WA