RE: make offer form
Actually, if you read the offer form it states NOT to use the form unless you are serious. We receive so many offers back and forth that a better solution would be to have a "Conditional Acceptance". This would allow you to mark the item "Sold" pending payment. If payment is not received, it goes back live.
Having said that, our current system is really designed to do that. If you mark an item sold, you can go back and cancel the sale and revive the ad with no harm. You have the bonus of being able to rate the individual as well. No computer tool can substitute for human judgment. I encourage you to still use the forms but possibly wait until marking something sold. That way, you can accumulate backup offers if the first falls through.
Michael