I can certainly agree the whole thing is slipshod from the start with no firm definitions. and it's by design. But the Rats can't get away with calling jaywalking an impeachable offense because their own voters would revolt, even from them.
As of right now, with the entire Mueller report out, there's nothing to safely pull the trigger on Impeachment. Pelosi knows it. Her thug Nadles is still trying to pull blood out of this turnip. The redactions were far fewer than I had expected so I have much doubt there's anything redacted that would tip that scale.
There's the money shot.
YES he could be brought up on jaywalking... but like you say, such a charge would be so superficially political, that they would do terrible damage to themselves...
It brings the Clinton impeachment to mind. Republicans hated him so much that they went for it without a viable charge. They got him (sorta, no conviction), but they damaged the Republicans themselves far worse.
But it IS purposefully vague... Say a president got drunk off his ass and was found butt naked in the middle of the white house lawn the next morning with an equally naked senator's wife.
By today's standard, there would be no pressing crime in any of that, but as a matter of behavior and comportment... an impeachment over such an incident would be legit.