> What changed that I was unaware of? As far as I know, it still makes traffic flow much more efficient in most situations.

Right turn on red was mostly implemented to avoid having cars idling waiting for a timer-only light to turn.

Between modern cars with fast engine stop/start and modern sensor technology which triggers lights when there is no opposing traffic, there are a lot of good reasons to remove that rule again.

You would have to add a right turn arrow for your logic to pan out.

>Also, at least where I live, the walk light wouldn't be on at the same time as someone turning right on red that would be going into my path.

What guarantees this exactly? I'm having a hard time seeing how this is possible.

If they are turning right, and my walk light is on, then they already have a green light.