Estate Agent Fees

Selling my house and going to shop around for EA and their fees have 3 in mind whom I am going to contact

GWD Valued my house but only have 2 offices
Gunne Solicitor recommended these, he is not on Commission
DNG

What are the main questions I should ask and has anyone dealt with the above
 
Hi There

I never areed a fee with my estate agent and never signed anything. He did one viewing in a year and got an offer he now wants to charge me1.8%. He says if I dont accept he will tell the clients the house is no longer for sale Im really annoyed with him this is in the midlands anyone have any experience of this? ObviouslyI got offered a pittance and haveing lost a fortune already would like to salvage something