Skirmish-Focused Thoughts:
In skirmish I want more than 2 attack die for a 7 cost figure. 8 health/4 movement/surge for 2 damage/+2 accuracy is all stuff you can get on cheaper figures generally, so you're going to need to get a lot of value from Contempt and Punishment. Luckily, I think they're both good abilities but I'm not sure if they justify 7 points in skirmish.
On the plus side, this gives the gives the Merc faction access to Stun. It seems like you'll usually be choosing Stun as the condition anyway, but the flexibility is good, as is the ability to use extra surges to add more conditions. You could easily Stun, Weaken, and Bleed a figure on a good die role.
So I'm not sure about Dengar, he's certainly not a powerhouse for his point cost as Boba is…
Also, for skirmish, Punishing Strike seems expensive for 2 points, I think it would have been very powerful at 1 point. It does upgrade your Bleeds to Stuns though, which is really good considering many Merc figures can inflict Bleed (Transoshans and Nexu are the most common).
Dengar's command card seems pretty good, but you do have to survive an attack which limits the window of use significantly. The targeting restriction is also a downside: you might not want to shoot back at the figure shooting Dengar. It's fair for 2 points but not amazing. The other command cards both seem bad because they're either only situationally good or because symmetric points are just bad.
Also, FWIW Both Dengar and his Punishing Strike could improve in the future if powerful new Harmful Conditions are introduced. As far as we know, Stun/Weaken/Bleed are the only ones in the game now but who knows about the future.
Update: after the recent errata for Gaurds and Sabs, Dengar is looking a lot better. We'll see soon just how much better.
Edited by nickv2002