I'm not sure what camera will best meet your needs. Based on the dollar amounts floating around, I think your main consideration is between a camera with interchangable lenses or an all-in-one. IMO, if longer focal lengths are of interest, you can most likely use smaller image formats (four-thirds/DX/etc) and get a camera with an integrated zoom lens. If wide angle shots are of more interest, you probably need to seriously consider a (gently used) full-35mm frame format camera.
OTOH, there's a lot of people going bonkers over the Fuji X100 (Which is more than $500, but whatever...)
Edit: I see you answered one question already..