In my opinion, I'm happy corsairs have A- in parrying (matching them with ninja, thief, and samurai). I love soloing as a COR/NIN.

Ninja has multiple shadows and high evasion (A-) to work with.
Thieves have insane evasion (A+) and job traits that add on to this.
Samurai, well, I don't see many of them as /NIN anymore, sadly, but that Seigan and Third Eye are pretty nice.
I think it would make more sense if COR got a little bonus to parrying. It could be a really good strong point with them.

With that in mind I'd like to offer the following suggestions:

Job Ability
lvl 72: Duelist's Roll/Pirate Roll - Enhances parrying for party members within area of effect. (Similar to Ninja Roll)

Job Trait
lvl 55: Fencer (Hard to believe that BRD has this, but way to go BRD!)
lvl 77: Tactical Parry

These are the only bonuses I've been wanting for COR (mostly the parry roll) since the announcement of the level cap increase. I would like to know how the community feels about this.

Also, I know a lot of CORs use /DNC and I am happy that it totally works out for them.
Yes I am aware of it, but I absolutely hate /DNC and wouldn't be caught dead with it (on any main job for that matter). Please try to ignore my feelings for /DNC when evaluating my suggestion.