why does it keep saying "Cannot load SteamworksAPI.mfx. this object might need an external program or library not yet installed"

Seems unfunctional. Likely a nuked release.

As Delta mentioned, when you start any fight, no character is present, you only see an empty stage with the countdown.

Also, perhaps the program did too well on respecting the DPI settings of the OS, that if you use an extra large value (mine is 175%) the fonts in the game become so large that they got clipped off, it's unreadable.

There is English support via the English interface and English subtitles.