Create a shortcut visualizer like this?

So, I would like to create a shortcut visualizer similar to the one in this video: (you really only need the first 15 seconds)

I do a lot of tutorials in Premiere Pro and I would love to have a shortcut visualizer that accomplishes three things.

  1. Have the ability to define the name of a key. For example, if I hit S, it speeds up play back by 2x. Most shortcut visualizers would just show "S" this isn't extremely useful to someone watching my tutorials since my shortcuts are all mapped to things I prefer. So I'd like to be able to define what "S" does and when it's pressed, something pops up like "S - Shuttle right" this way the viewer knows what the key does.

  2. Have the ability to define the area of the screen that these notifications pop up on.

  3. This is getting a bit more picky, but it would be really nice if I could define how many pop ups can stay on screen. Ideally 3 could always be on screen at once and then once you have 3, it would cycle the oldest one out and bring in the next one. I don't really like when something just fades off screen. It'd be nice for the viewer to see the last 3 keys that were hit at any given time.

Originally I was going to ask if there was a way to do this in KM, but the only thing I came up with was using the notification action which really isn't all that elegant. Notifications are pretty big and ugly.

I know there's a lot of smart people here, so I'm wondering how hard something like this would be to create as a program or either a script? Or maybe it is possible with KM and I just don't see it?