you need to know that buyers and looking for value. So Realtors are showing homes that they think represent value. The homes that have sold during the time your home has been on the market were voted by Realtors and buyers as having not only value enough to show, but value enough to buy!
So your Realtor should be guiding you on this. The longer your home is on the market, the less value it retains
let me know if you have more of a specific question.
Not sure I understand your question. Are you asking why only one person who was shown the property was qualified? Please make the questions a little clearer so that I am able to understand what you are asking.