Can you add an image of the HTML source of the anchor tag as it's rendered on the page?

You have to update the Day CQ Link Checker Service (com.day.cq.rewriter.linkchecker.impl.LinkCheckerImpl) to allow for tel: links.You should also change the content of the href to @ context='uri'

Have you tried putting a cq:editConfig in place and not providing the delete option?

First off, I would maybe try a private browser window and make sure it's not a javascript caching issue.Secondly, I would take a look at your node structure and make sure that the page has a valid cq:template and sling:resourceType.

This typically happens because 2 xtypes have the same namespace and therefore AEM tries to load both.  I've seen this with ACS Commons installed (with their multifield panel) and also a custom multifield being installed.

Not to my knowledge with the query builder.  Instead of setting the value to blank, could you set it to "none" and query for "none" instead?

1.  You're correct.  I think the point is that the content itself is located centrally and available for other authors to see, can be controlled by permissions, and you can create snippets based off of a content fragment and variations of a content fragment.  From an authoring standpoint I don't bel...

I think the difference is that you removed the value, meaning that the property name still exists on the node but has an empty string - when you save an empty value using a dialog, the property itself is removed - so the not operation looks for the property not being on the node at all.  Go ahead an...

I think the point of content fragments was to be able to create pieces of content that could potentially be used in multiples places, with or without slight variations, and house them in a single location, rather than prior where you'd need to use a reference component and have the author navigate t...

This is very vague.This is also the reason you don't implement custom multifields, because the API's are constantly changing.