"Quick actions" in description or in a separate quick action bar

Possible use cases:

ITEM_X = [ estimate | up-/down-stream dependency | owner | tag | status | sprint | portfolio-item]

As a power-user writing a story,
I want to add an ITEM_X inline in the description,
So that I can create stories faster with less mouse clicks.

As a power-user looking at my team-room,
I want to press a key combination to open a quick action toolbar,
so that I quickly edit a story with as few steps as possible.

In many ways it could function much the same way as mentions and links work with the @<storyname|username>


I'm writing a story in the description, and wants to add an estimate:
1. I write #est
2. A autocomplete box shows up and completes the command
3. I write the estimate like "4 pts" and press ENTER
4. The estimate has now been added to the story.

At any random location (or in my teamroom) I want to change the owners for a story
1. I press the key combination ctrl+shift+p (as customary in code editors)
2. A quick command pop-up opens up, prompting me for commands (examples could be shown below)
3. I select the story by writing @s-12345 (it autocompletes to help me know that I've found a story)
4. In the same line I write #est 5
5. The story now has an estimate of 5
6. The quick command pop-up closes
7. When opening the quick command box again, the latest stories and commands are being suggested (select with arrow down and spacebar to accept)