Hi!
It would be great to have unindent so that when I press shift - tab the text on the selected lines move one tab left.
I requested that about a year ago, let’s see how well your request goes.
Thirded 
Along with a block uncomment. And preserving the indentation when block commenting (selecting the lines then selecting – from the ‘extra symbols’ button)
Note that the issue tracker (link near top of page) is the right place to make suggestions like this.
Done! That’s not too complex for me.
Are we supposed to add stuff to the issue tracker on our own. I thought we had to suggest if first, get comments from other users, and then @Simeon would say it could or couldn’t be done. Then it would be added/not added to the issue tracker. If we can just add what we think of, then I would have loaded up the issue tracker long ago.
@Simeon I think we went through this way back, and the issue was a difficulty in reading the keyboard. I believe the tab key returns the same value whether or not shift is activated, and it wasn’t clear that you could detect the shift state independent of a key press.
@dave1707 My take on it is that it is important to get stuff on the issue tracker so that TLL can easily keep track of it, and it is important to discuss stuff here so that TLL can get a rounded view of what is wanted. So there isn’t a system where one has to come first, just that both are useful. Indeed, you could put something on the tracker and then start a discussion saying “I’ve just put this on the issue tracker, I thought it worth discussing it a bit as well as there are some things I’m not sure about.”.