Don't know if anyone cares now, but I successfuly patched the nba play by play code rom to avoid the nasty hardware security error, so I got my game running again. Amusingly, only a 4 byte patch is needed for it. But you have to add more code to actually make the rom code patch the code decrypted in ram:
Also, looks like the security key for it is nothing more than a serie of zeroes...