I would go combat on the rogue.
That way, you can do reasonable damage from the front or back.
The rear will still be better damage, due to less dodge/block/parry.
Then again 26 expertise (not rating) and you're immune to most of that.
And you can get 10 expertise (not rating) from talents alone.

For bosses a combat rogue will:
Sinister Strike 2-3 times... Slice and Dice.
Sinister Strike to 5 combo points... Rupture
Sinister Strike to 5 combo points and....
a) Slice and Dice if there's 11 or fewer seconds remaining
b) Eviscerate if there's 12 or more seconds remaining on SnD.

For a macro, not sure exactly.
Probably a cast sequence, reset=target/combat.
Sinister Strike x3, SnD, Sinister Strike x3, Rupture.
Something along those lines.

#show
/assist (assist method of choice)
/castsequence reset=combat/target Sinister Strike, Sinister Strike, Sinister Strike, Slice and Dice, Sinister Strike, Sinister Strike, Sinister Strike, Rupture

I've personally found Wound/Wound for PvE and Wound/Mind Numbing for PvP to be the best poisons.
Elitist Jerks recommends Wound/Deadly, for PvE, but personally that lowers my wws dps every time.

Be sure to use Adrenaline Rush, Killing Spree and Blade Flurry often.
AR and BF combine very nicely. KS and BF combine very nicely. AR and KS do not combine well.

Combat - Fan of Knives spec, might be worth considering at 80th.
It is extremely good at interrupting casting, and making life miserable for groups of casters.
It's lower dps then Combat or Mutilate spec though.

Close Quarters Combat (Daggers and Fist Weapons) is slightly higher dps then Swords.
Other weapons are quite a bit behind these two options.
Most consider a slow Fist weapon (primary) and a fast Dagger (off-hand) to be optimal.