On further reflection I do not see how a carrier can deny a claim based on the fact that the mortgagee was not endorsed as an additional insured on the new buyer's policy. 

I had three Captain's Licenses, up to 500 ton Frieght and Towing with all kinds of other endorsements.

They also got the backing of various other agencies such as AASHTO (Amercian Association of State Highway Officials) endorsing it, and finally they made their data proprietary instead of using a published open format.

He is also endorsed by our local rental association.

A policywith a higher premium may be a better deal if it does not have a wind deductible.There are many endorsements that are available on the homeowners policy.

Usually a relatively expensive endorsement is necessary. 

The link is http://www.realestateinvestorswebsites.net/which I found searching for key words, and it was in this is a Bigger Pockets blog post...http://www.biggerpockets.com/blogs/640/blog_posts/27086-how-to-attract-leads-through-your-real-estate-investor-websiteIs this company legit, and Bigger Pockets endorsed?

The value speaks for itself if you investigate to any real extent. ...I have looked at the list of posts here on BP for both Doug Leedy and @David Dachtera, and it seems the vast majority of what they have posted is specifically things to endorse  / defend Renatus.  

Lastly, and this really applies to those with many locations, they work on an endorsement-basis.  

I'm surprised that you're so threatened by someone providing information regardless of whether or not you endorse the concepts or not.