"If you can’t get the client to provide any of these answers, I’d strongly suggest that you consider declining the project."<p>That's exactly what I was thinking as I read the list. I've dealt with projects where people either couldn't answer those, or couldn't be bothered to answer those questions. They're vital to the project and need to be answered by someone. Unsurprisingly, I (as the developer) rarely answer them correctly.
Good questions, but I would go a step further: a lot of clients do not have a good feel for what a web site might really do for them. An important part of the engagement is to act as a facilitator to help the client identify what their needs really are.
Sometimes clients are expecting you to answer these questions for them because they don't know. I suppose what's what's more important is to define your role as a website-maker?