[Martial Arts] Defensive overkill

[mlangsdorf]

a. It seems reasonable, but the drawback on a Defensive Attack is less damage, and Feints don't do any damage. I'd probably rule that you Feint at a -2 penalty and call it good enough.
b. Ripostes and Counterattacks have to be the first attack after the parry, so I don't think you can Parry and then Rapid Strike/Extra Attack a Feint and Riposte/Counterattack. However, half the Riposte penalty applies in quick contests, and feints are quick contests, so you could perform a Riposte Feint. Giving up 4 points of defense for 1 point of bonus in a quick contest seems sub-optimal to me but sure, why not?
c. Ripostes are useful when you have stupid high defenses (Fencing Retreat + Shield + Enhanced Parry + Combat Reflexes + high skill + possible Defensive Attack or All-Out Defense) and you can afford to take a hit. Counterattacks are useful when you've bought up the technique.
d. Sure, a Riposte or Counterattack can be defensive. If your foe is lightly armored and you have a poisoned weapon or something (melee spells, too) so that you don't need to do much damage, using a Defensive Attack to set up your next Riposte is a good idea.