Seb croaking dirk vs blade of the green dragon eye
 

For a lvl40 Rog to use in the offhand all the way up to 60. Not planning on replacing it ever, so I want to make sure I get this one right.

I looked for a chart like I see for monk weapons. Couldn't find.

Rog skill caps piercing higher than slashing every level, ya? Is that worth taking into consideration?

13/24 = .542 (Green Dragon Eye)
10/18 = .556 (Seb Dirk)
14/25 = .560 (EoN)

It's not even close. Green Dragon blades are typically overpriced for their actual damage output. They look nice and that's the only reason to use one.

Seb dirks are high agro, high dps. Handle poorly on damage shields.
EoNs are lower agro, high dps. Handles damage shields.... better.

Seb dirk agro is manageable. The DS difference only really happens in hate / sky.
EoN / Seb dirk perform the same otherwise. Personally, I prefer the dirk more.
Best weapons you'll get in Kunark outside of VP and they'll hold up well in Velious.

I don't think that's the case here. You'll 250 cap on piercing, slash, and blunt. It's a good idea to keep slashing skilled up with pierce. Blunt doesn't have as many good options.

Cecily is wrong, blunts are always a good option

Wasteful and reek.

My rogue uses Thornstinger in Primary and Epic in Secondary. Overall pretty happy that parses more than Epic+EoN. It does open you up to getting raped by damage shields on a raid if you don't have someone either dispelling them or doing Mark of Karn. If your guild does sky or you can afford an MQ you could consider that - MQ price on Thornstinger is roughly the same as the price of an EoN, possibly even less.

The obvious other alternative would be for you as a rogue to repeat the epic quest for MQ until either an EoN drops or until you get enough money to buy one. Just need some friends to help you with final General slaying.

There's nothing wrong with blunts, but secondary usable rogue blunts with ratios to match the above weapons don't exist in kunark. Best out there would be jade mace at 9/18.

Cryatalline Short Sword or Green Jade Axe are also good secondary weapons if you don't want to splurge for big plats.