I would specifically be interested in seeing how the bonus to critical hits was applied to Streetfighters and I would like to add a bonus to a class while invisible and could learn from studying the implementation of the Streetfighter's bonuses while Flanked.

all abilities will be in the abilities.gamedatabundle

Adding a new ability would be done by adding it to the progression table for that base class, which is in the progressiontable.gamedatabundle.  Look for "pt_fighter" or "pt_rogue" or whatever

Cheers,

Grape