Fair points, though I tend to reserve the comma for instances where a cut/new shot doesn’t make sense and as such ought not to be implied.
He pulls off his helmet, PANTS HARD.
Her eyes widen, face glistens with sweat.
As for the run on case, I tend to just leave no punctuation, and keep the first word of the next scene’s action like so:
Joe turns to watch Jane move into
INT. BEDROOM - NIGHT
where Jane rips a suitcase off of the wardrobe.
Like you said, everyone’s going to have their own styles. Main thing is remaining consistent within a piece.