Are you sure you're playing on default settings? Please compare your replay to this one: Link
Watch out for the midboss which initially already has an 8-way shot from the very beginning compared to the 4-way from your replay. Also, you only get four flowers from him, but you usually get 8 because the rank is on max by then. All enemy bullets seem to be very slow as well. Could it be that the game is easier with english text? You can change the game to japanese text via dip switch settings.
Very peculiar. My PCB is the same as MAME (considering the working dump in MAME is from my PCB, no surprise), so... I don't know. All DIPs are off, so I'd say that's default settings. It's possible that that video (and your PCB, I presume) have a newer version of the game (or maybe older?) that is harder. It's also possible that the bootleggers lowered the starting difficulty on my board. Lots of questions.
It seems to me that starting rank is set too low, but as soon as you exit stage 1 everything is identical to in that replay. Eng/JP makes no difference
That's exactly what it seems like, yes.
This probably makes all scores done on the Mame version not comparable, right?
If you'd like to do this, I've no qualms.