gimp_gate | Recommended Wacom settings?

So I just got my hands on a sexy Wacom tablet. I've been toying around with it in Gimp, but so far it's leaving a lot to be desired. I think this is due to the way the settings are set up. My computer reconizes it fine, but there's a lot of things I don't understand about the default settings and general behavior and haven't had much luck finding information.

Here are some of the things I have questions about. If anyone has any answers, I'd greatly appreciate it.

1. What's the difference between "Window" and "Screen" Mode? Why is "Screen" the recommended one? (I've seen a number of (outdated) basics of setting it up, and they all say "Use Screen mode," but none explain why, other than a vague "Screen generally works better." What makes Screen better?)

2. Gimp always switches to "Airbrush", "Pressure-based Opacity", and black foreground color when I switch between my (non-Wacom) mouse and the tablet. Why is it doing this, and how can I change it? I'd prefer Paintbrush and Pressure-based Size as default.

3. Is there any (good, recent) documentation about settings that work well for artists that use drawing tablets?