Will more articles be added?

Absolutely yes! There are plans to add more articles over time, covering different topics that might be interesting/useful to people learning Thai.

In the translation pop-up, what are the strange characters between the forward slashes?

This is IPA transcription, a standardized way of representing, in written form, the sound of a word. In theory, it’s characters can be used to represent every sound in every language. You can learn more about IPA and how it applies to Thai from Stu Jay Raj in his Thai Bites video.

When I try to highlight a section of text, the whole paragraph or page gets highlighted.

Instead of highlighting left to right, try highlighting right to left. This is a result of the page having been parsed and prepared for the translation pop-ups when the page initially loaded.