Stas,
That is really good info and ideally should also go under https://www.wikidata.org/wiki/Wikidata:SPARQL_query_service/query_limits
and I would say that even better would be a new page about "Best Practices" should be made and added under "First Steps" section here https://www.wikidata.org/wiki/Wikidata:SPARQL_query_service/Wikidata_Query_H... where that "Best Practices" page would also have a link and blurb about "query limits" page.
-Thad