Yesterday I reported a, already removed, bug report about a what seemed like a bug at the time. I got the notification that I was trying to convert from one lossy format to another eventhough I was working with APE files. As it turned out, I accidentally assigned a shortcut to the '[context / now playing] - Convert - Convert to...' action, while this should have been the '[context] - Convert - Convert to...' action.
This happened because the list of actions was rather long and I moved through the list too fast, selecting the first 'Convert to...' action I could recognize. At the time I didn't know there where actually three different versions of this action.

It seems to me that the Action list is too small for the amount of available actions leaving users with no clear overview.
What about merging the 'Assigned shortcuts' and 'Action' list into one? This would allow you to increase the height of the list to a bit more useable and reasonable size, creating a better overview.
Merging the two lists would make the 'Type' and 'Action' column of the 'Assigned shortcuts' list redundant leaving you with just enough space to put the 'Key', 'Modifiers' and 'Global' column next to the actions. The 'Add new' button would also become redundant and the 'Remove selected' button can be positioned next to the 'Global hotkey' checkbox, again gaining more space.

You would loose a list of just all the shortcut assignments but since you're gaining a better overview of all the actions it won't be much of a problem to locate the assigned actions.