Hotkey script manager for Mac?
Alfred can at least get very close to what you want. You do need the Powerpack license to use workflows in it (~£19).

It is somewhat manual, but to me it doesn't seem too cumbersome...

Give each script two triggers: Keyword trigger and Hotkey trigger and you can then write what the shortcut is in the subtext field of the Keyword trigger (for example). This way every time you use the keyword trigger ...probably because you forgot the shortcut, you still get a reminder of what the shortcut key combo is.

Because the keyword I chose was similar to the Date and time preferences, it shows up too, but Alfred does adjust the order based on use, so after first use, the script would show up above the preferences given that I've never opened date and time preferences through Alfred. You can also exclude files from showing up in Alfred. For example,
 I got a workflow that opens dropbox folder... so I excluded Dropbox.app from Alfred because it is set to open on startup so I have no need to open it through Alfred.

Obviously every time you change the shortcut, you have to edit the subtext too.



If you want to trigger automator workflow from alfred, I believe this is still the best method: link. It's been a while since I looked into it so there is a good chance my info on this is outdated.