Regarding point 1, that depends on your eyesight and the site you're viewing. I can read 95% of sites at the default zoom, but a couple with small fonts require me to zoom in. But then I'm a (relative) youngster, with fairly decent eyesight.

I used to work with a guy who ran a 19" CRT monitor at 1600x1200 resolution quite happily, and I couldn't read it. Conversely, I work with another guy who runs a 17" TFT at 1024x768 instead of the native 1280x1024.