[Plugin: W3 Total Cache] Documentation?

There’s nothing more than those resources. Can you be specific about what you want to do?

#1) Varnish: When using an array of Varnish caches, with cache purging enabled, is there a recommended VCL script?

ditto the “cache control policy” setting

https://www.varnish-cache.org/trac/wiki/VCLExamplePurging should be helpful.

Thank you for the lead, Frederick! I was just embarking on a long list of docs on Varnish, both on the main site and on https://kristianlyng.wordpress.com (a blog by one of the developers).

Does W3TC send wildcards in its PURGE requests? More to the point, does W3TC send the URL as a literal string or as a regexp? (which impacts whether I use the 2nd or 3rd code example on that page)

No it doesn’t, but I’m working on that.