I'm completely new to bracket and twinking itself, but my general philosophy about itemizing as a rogue is to get as much agility as possible. Also, I see a lot of rogues use those GF'd 1 handers. If you do that, I think you are dramatically gimping your ambush damage for a slight damage increase on hemo. That trade isn't worth it imo as ambush damage is still SUPER important at 39 (even though I'm sure lots of people would disagree). But anyway, just from looking at your gear, I would reccomend:
GEAR
1. Switching neck to WSG neck (more agi)
2. Getting the cloak from Mara (haste is useless)
3. Bracers are nice but the +agi ones would have been better
4. Switching gloves for gloves of Holy Might
5. Switching boots for AB Boots with Crit/Agi and Enchant them with Dexterity
6. Swapping out Aquamarine Ring of Monkey to Agility
7. Swapping other ring to either WSG Ring or DM Crit/Agi/Stam ring or Bag ring of the Bandit
8. Getting Searing words trinket from Scholomance
9. Getting a second on use trinket (there's one from Scarlet Monastery and one from a quest, both are good)
ENCHANTS
1. Shoulder enchant is fine but I prefer Aldor one
2. Cloak enchant is good, I was also considering getting that one over 9 agi, both are good
3. Swapping out chest enchant for +4 all stats
4. Switch bracer enchant to either Greater Assault or +8 agil
5. Dexterity on boots once you get AB boots
SPEC
You are playing nightstalker, which I think leans more towards the 19 ambush playstyle. If you do want to play with those weapons, I think Subterfuge is better, as you don't need the extra damage on opener.