I think that the wording on the fabrics about "personal use" etc. is there in part to protect the fabric manufacturers from being sued by the owner of the design/license (such as Disney, MLB etc.) ... this is a lawsuit-happy society that we live in and as result, we get things like this happening.
As to those cease-and-desist letters, I've received three so far. Two related to selling fabric, and one for an item that I sewed.
Who am I, and what do I do? I sell fabric on the internet. And I sell appliance covers that I've sewn from fabric.
The first two cease-and-desist letters related to "red hat fabric". You may remember a few years back there were a bunch of "red hat" fabrics for sale. It seemed every fabric company made a collection that year, and none of them were named "Red Hat". Betcha they got the same cease-and-desist letters I received!
Basically, I got one in writing (by mail) and the other arrived as a middle-of-the-night e-mail. One was from the "Red Hat Society" and the other from the "Red Hat Ladies". Both alleged trademark infringement, and demanded that I stop selling the "red hat" fabrics that I'd already purchased. However, trademarks are issued only for a specific set of products or purposes, not as a blanket-covers-all. Both groups had trademark status ONLY as social groups. Neither had been granted trademark status for ANY products, of any kind, at all. So they were just blowing a lot of hot air. But I didn't know that, at the time. And so I researched, and also came across the Tabberone website. And I'm so glad they posted all the information for us to read!
The other cease-and-desist letter was because I was making covers for George Foreman grills. Interesting, the letter did not come from the George Foreman company! It came from an individual, who alleged that I was making a knockoff of his idea for a "protective and decorative" cover that was designed to look like a beanie or cap. This letter had about a dozen clauses describing his cover... and my covers differed from his, in EVERY clause. So clearly they were entirely different than his covers (which were not even in production). I showed this letter to my attorney (yes, I had to pay to do that!) and he said that the whole thing was an attempt to find someone to produce the covers for them, because the letter included an offer for me to license with them. Gee... what a scummy way to find a manufacturer! Obviously I did not partner with them!
Live and learn...