The article is for yui & can try applying same logic to less.https://helpx.adobe.com/experience-manager/kb/upgrade-yui-compressor.html

Please engage with official support & This needs screen sharing.

* Does the cug protected pages are handled by /etc/maps rewriting?* Could you please add "html" & "htm" to the property Path Info at [1] and verify.* Go to http://<host>:<port>/system/console/configMgr/com.day.cq.auth.impl.cug.CugSupportImpl* Unbind it then save it.[1] http://<host>:<port>/system/co...

Configuring on aem side for content/imf/en does not help & you need to configure the destination at idp also.  As informed earlier if group passed from idp is adminstrator then there is a problem please file support ticket. 

If the group attribute passed from saml Or default is configured as administrator then it fails. Issue is logged internally & should be fixed as part of sp1.  Either send non admin group or file a support request to get an hotfix for you.

You need to install service pack & couple of hotfix. Please wait till sp3 or file a support request.

Sounds like bug introduced due to csrf framework. Please file support ticket.

As per doc the approach is [1].  I doubt doc is valid & upto date.  Please file support ticket to track & get official statement from engineering team.[1]   https://docs.adobe.com/docs/en/aem/6-1/administer/integration/cq-as-portal.html

enable debug log Or use http://adobe-consulting-services.github.io/acs-aem-tools/explain-query.html

Hmmm..  Sorry missed the description.   From Explain query output your index not even listed that means your custom nt:base rule would over shadow the default nt:base rule.   Looking into your query & based on path "/content/demo-spark/jcr:content/bgimage"  I am assuming "demo-spark" is cq:Page. So ...