As any painter will tell you, prep work is just as important -- if not more important -- than the paint application itself. If the paint on your house is chipping or peeling, it needs to be scraped and sanded smooth before applying a new finish. In most cases, you won’t need to remove all the existing paint, but scraping, sanding, patching, caulking, and priming are critical steps that take place before the start of most exterior painting jobs.
If less than half the old paint is left, however, it may be worth stripping it all off. Guertin gets rid of stubborn remnants using shrouded grinders (like the PaintShaver), infrared paint strippers (such as the Speedheater), or chemical strippers (like Multi-Strip), then smooths the wood with a course or two of sanding. When siding (or bank accounts) can't take the shock of a total strip job, Rich O'Neil, of Masterwork Painting in Bedford, Massachusetts, has successfully hidden rough, well-adhered paint under Peel Bond, a thick primer.
Color is always the first consideration when painting a home. Most paint manufacturers offer samples to try that can allow you to make a more informed decision. Because light within a room may vary from wall to wall as well as from day to night, try painting a large piece of poster board in the color or colors you are considering. Move the board from wall to wall and look at it for a minimum of 24 hours at a time in each space to make sure you like the color before committing.
I disagree with your criteria to hire a painter. A prompt returned call is nice but does not indicate the quality or fairness of the painter. As far as a written estimate, that should be more of a qualifier for the bid versus an evaluation criterion. I'm not sure one would have favorable results by hiring a painter on this basis. As far as the bidding process, change orders should ONLY be used if the customer requests additional scope (PMP 101). Angie's list should consider asking reviewers if/how much they were told to pay compared with the estimate. Unfortunately, there are a lot of contractors that are unethical and need to be accountable.
This painter Scot never came and finished the job. Texted me at 6:30 in the morning saying that he isn't able to do the job I gave him. I would not recommend this painter to anyone. I will make sure everyone I know won't use this guy. He is the worse business owner I have ever met. I don't know how he is in business. Be very careful of this guy Scot. Don't trust him and don't pay him for anything for any work.