All great ideas studtrooper and 750. I know it’s trivial but it’d also be cool to have a Colour Edit mode and be able to select all the different versions of the Music (i.e. CPSI, CPSII, Arrange, maybe HDR and PC version music too) and be able to customize it by separate tracks (e.g. CPSII for Ryu’s Stage, CPS1 for Character Select, Arrange for Zangief’s Stage etc).
Have loads of Dip Switches to customize the experience both gameplay-wise and cosmetically ala the Dreamcast version and HDR.
Oh and be able to play as the ST version of characters in their original colours (e.g. ST Ryu with White GI).