ESC key functionality in the Play menu
When in the play menu (picking a game mode to play) when you press the ESC key it counts as two button presses.

Depressing the key counts as one button press, then letting go of the key counts as another. So pressing the key and letting go how you normally would, counts as two button presses and takes you back two pages.

Note: This only happens when you're in the menu where you select playlists for co-op, versus, or competitive. Not in the community server browser or in the play menu itself.

Right clicking someone's name in the scoreboard
For example - if you want to view a player's steam profile. Once you right click the player's name in the scoreboard and the menu comes up - you try to click 'View Profile' and it will just scroll through the buttons. You have to spam click the 'View Profile' button for it to work.
It seems like the action of you holding tab to keep the scoreboard open is not being filtered out when you're in the UI to view a player's profile or report them.

Customize menu automatically equipping anything you view
This one is especially annoying, and I also noticed it during the CTE.

It's best to let the video speak for itself

Please note that all I'm doing is clicking different clothing categories and it's equipping different items on its own.
It seems like it automatically equips the first item on the list that you own.

Power plant is worded incorrectly in the replay menu