In addition to your own answer:
Jewelers (and most chain mail workers that I know, including myself) use a type of pliers called "chain nose pliers." I don't really know why they have that name, but they have nice pointy tips for getting into the rings and smooth surfaces on the inside. Here's an article about chain nose vs. round nose pliers: http://blog.consumercrafts.com/jewelry-main/tool-comparison-round-nose-vs-chain-nose-pliers/
Also, using a glue gun probably won't work well, but you have the right idea there. Instead you want to look for a product that is designed to coat the metal on tools. Here is a short article about this concept. The product used in the article, and that I have also used in the past is called "Tool Magic," but doing a search for "rubber coating for tools" turned up a bunch of different products that could work equally well. I would test whatever you try to make sure you can remove it easily like she mentions in her article, but otherwise use whatever of this type of product that you can find.
The article also mentions using tools like the one that you linked to in your answer, but I, like the author of the article, have been disappointed whenever I have tried those tools--mostly because the additional surfaces made it difficult to work within the fairly restricted confines of the rings used for chain mail.
Edited to add:
Not specifically needed for answering your question, but I highly recommend taking a look at The Ring Lord website whenever you have a question about working chain mail. I will state that I have purchased from them and found their products really nice, but more importantly, they are the first place I go when I have questions about making chain mail. They have great pictures that make it clear how ring sizing works, good tutorials and even their own forum on chain mail. So, whether or not you purchase from them, I recommend bookmarking it as a great resource for learning about chainmail.
Plus, for any knitters who might be reading this, their small rubber rings make perfect lace stitch markers and much more price effective than any other resource I have ever found.