1.) I like the idea, because the sliders aren't very much fine-adjustable in the first place.
2.) Yes, artifacts only cool down 16h now (although the artifact text still says 24h)
3.) Not sure, if all those numbers are actually checked by some user (maybe they are just the extension of observed patterns), but there are at least two players managing a database of artifacts, so see yourself if you can find any interesting artifacts in there:https://www.warzone.com/Forum/494875-artifact-database