1. It’s just JavaScript so you can fetch stuff dynamically too (see https://observablehq.com/framework/lib/duckdb). But yeah, only client-side. (Though see https://github.com/observablehq/framework/issues/234.)
2. Sure, it’s all open source, I bet you could make that work. Or `yarn deploy` to Observable and configure sharing there (though it wouldn’t let you charge others).
3. Yup. Which is part of the appeal of model of running data loaders at build time: you can query some private data and viewers would only be able to see the final result set. (The lack of something like this has always been a huge problem for Observable notebooks. You’d make some great query-driven charts and then couldn’t make it public without some awkward manual dance of downloading and re-uploading a file to a fork of the notebook.)
4. I wish I knew! It’s being tracked here https://github.com/observablehq/plot/issues/1711. Lately there’s been a lot more work on Framework naturally but now that that’s out…
5. Another good question. We’re definitely interested in tailoring it more to this sort of use case but lots is TBD!