hmm. okay, and what about coin symbol in the upper screen in smb1? Yup, i know about '0 sprite' situation, but is it possible to remove this?
Possible? yes. Practical? not really.
The best thing you can probably do is sort of hide it by shrinking it so that BG and sprite coin graphics are 1 pixel in size (leaving only the upper-left most pixel that both the BG and sprites share). That will reduce the drawn image to a 1x1 pixel artifact on screen -- which would still be pretty visible, though.