When I go to the front page of Stack Overflow, I normally hold down ctrl and hit each of my tags so I can pull up a different browser tab for each tag that I have in my "Interesting tags" section. About every third time I go through this sequence, I accidentally hit the 'x' next to a tag and delete the tag. If I had an option to lock the tags (or a tag was somehow slightly more difficult to accidentally delete) I could avoid this annoyance.
Perhaps the tags should only be editable from the user profile? Or one can add tags on the main page, but go to the user profile to remove them (or adjust their order, which I believe has been requested before).
You could completely remove the
'x' buttons by Ad-blocking the rule
The tag can still be removed from "Interesting Tags" by going to the tag's page, mouse-over on that tag, and click the ★ at the top-left corner in the info box.
The specific behavior that I use to open up the tags is to press the ctrl key and then hit each of my favorite'd tags. This causes firefox/chrome to open up each tag page in a new tab while not changing focus to the new tab. Similarly the shift key causes a link to open up in a new window.