Game was played on a PSX using an X-Station

The game has R2 set as a shortcut button(that as far as I'm aware can't be turned off) Besides giving Easy Inputs to various special moves this button also can be used as a Dash macro(Neutral R2) Because Dashing is treated like a special move you can perform an infinite by continually dash cancelling the same normal. Most of the cast can do this successfully, but Mermaid is a bit easier to land consistently than the others.

Time can definitely be shaved off. Ideally you would land the infinite until putting the opponent in a stunned state and end with the throw, into another combo while they are stunned. Doing this should save time on more or less every fight. This would especially make a big difference on the Makenpo fight, though the issue is dropping the infinite will usually result in you eating a Super which does ~90% In other fights dropping the infinite usually results in a throw, which while not damaging will eat up quite a bit of time. There is also plenty of time to save in the Garekky fight especially if you dodge the stomps and get maximum damage on the punish.