I’m no pro but I just did it without an agent and have in the past, but to answer your questions, yes and no. Also no on Scenario B.

You can also use a discount agent, one that gets paid by the hour. Some of the realtors that post here will work that way. When you say “area” if you mean you know what tract or what street and which model then you probably only need transaction representation but if you want to look into houses within a school boundary or something, someone is going to have spend time opening up houses with you (they rarely look like they do on the internet when you get there). You can also contact the listing agent and tell them you are going to offer less, factoring in a smaller comission, but they will be representing you, they are just more inclined to lower both sides of the comission since they are getting both.

With regards to scenario B, if a listing expires then the seller is unrealistic because nobody bought it at the listed price, 6% isn’t going to change that. IF you manage to get it for 6% less because you were without agents, you overpaid because if the difference between ask and market was only 6%, then it would have sold already. It’s better to buy expired listing as repos six months later.