The good thing with the system is that you can both bail out without difficulty if things like the situations that you mentioned happen. Also, when clients don't explain instructions well enough as to make the writer underbid considerably, the writer can ask for additional payment (which I have done several times).
Having recently visited essaybay (under a pseudonym) I noted that orders that are on offer rarely specify the full question or word limit.
You mean some orders, don't you? If you're presenting an unbiased observation then I'm sure that you also saw a lot of orders which were very specifically defined.
How can they do this and be sure that they will be able to do the work justice?
I agree. There are some unreasonable clients and some clueless writers on the site. However, having to sort bad clients from good ones on the part of writers and having to sort bad writers from good ones on the part of clients is precisely the most wonderful thing about the site. It gives people freedom to interact directly in an open marketplace. Writers are free to prove themselves to clients.
I can indeed confirm that I outed Jennifer for her consistent lies.
While I don't know anything about the site's owners, I do know that there are a slew of unverified writers on the site whose credentials are probably untrue. However, regardless of what you say your credentials are, the bottom line will always be how good your feedback is, and even if we take the feedback away, there's how well you interact with clients and convince them that you can write their orders well. When I was starting out, I used to even give free outlines just to prove that I can get the job done perfectly.
My only point is that WB claims that Academic Answers' products are overpriced where in fact, EB's rates are some of the lowest available in the industry. That's all.