2. You can run them locally. We're not running the scrapers anywhere, or storing extractions anywhere.
3. This is a big, big question. Right now, the answer is dependent on the use case. Rather than trying to make the world's biggest database, we're going to respond to community needs and build this kind of thing as it comes up.
4. https://measuresforjustice.org/ is doing something like this! We're interested in creating incentives for police departments to make their data more accessible and transparent.