Hello,
BBcode link is bugging me a lot because it doesn't remember text selection. Easy example which you can test even here in reply to this message (as devnet is using bbcode editor):
try to add some text to bbcode textarea,
select some word or text,
click on bbcode link image,
enter url,
next step will ask you to add description for url

In last step if you leave description blank, selected word or text from step 2 will dissappear, or if you will fill description with another description, then original description will be lost (which user can miss).

Suggested fix - remember text selection (just like you are doing with bold or italic buttons), when prompting show this selection in description box.

Please fix that in advanced mode as well.

Just in case, I tested this in Firefox and Chrome.
Thanks