Hey Welcome to WDT TannerCreative! Them are some good questions you've asked there.
1. I would say the first impression of your website and a portfolio with sites that show what you're capable of. A portfolio where you can view the sites really helps as you can see the results others are getting from the sites the company you're looking at has designed. Of course this is just my opinion as a customer looking at potential Web Designers online. I'm sure the results will vary depending on the persons experience and such.
2. Hmmm, I think it's actually good for a company to have a round about price range for a complete website and template and other services on their site so you can know a bit about what to expect before you go asking for a quote. I think this may be frustrating for some people and turn them away if you don't have anything up front because they don't want to get that $50,000 quote.
3. I'll have to let someone else answer that one.
4. Hmmm, I would have to say that would vary depending on the person and their experience. One person may look on Web Design type forums for recommendations and such. Someone else may just type "Web Design" in a search engine and go with the results they find there. There's probably quite the variety of answers for this question depending on the person.