Hi!
Second, are there any stats on the uptime of the WDQS SPARQL endpoint?
I am not entirely sure how you define "uptime" here? If you try to access query.wikidata.org, it'd be very close to 100%. That said, we had a couple of incidents where one or more servers failed, causing some queries to get stuck or be rejected, see https://wikitech.wikimedia.org/wiki/Incident_documentation/20171018-wdqs and https://wikitech.wikimedia.org/wiki/Incident_documentation/20171130-wdqs These do not take the whole service down, so I am not sure how they qualify uptime-wise.