If you are building one now, consider putting a gate on the hopper outlet and a way to remove the full hopper in case it jams.
Now Mine has a 3/4 HP motor shived to ~320RPM I have never had bushing issues other than to oil them occasionally.
And you might never have any trouble. Quite a few guys here have belted mills and have never had a hitch. It's just that I can see more strain on the bushings with a belted system vs a direct drive system.
Also with mine I have reverse, so if anything should jam, I can reverse it to free it up. Your idea of a gate on the belted system do make sense though
