1. Personally I run choke bomb instead of poison breath. With how much damage you do during dark strike, wouldn't the damage you do when starting the RB/LB/F right away with 5 stacks be more than the additional damage you gain from poison breath? it's about a 10k damage to 3k and poison breath has about a 2 sec cast time for BNS Gold. Choke bomb seems a lot more flexible while poison breath grounds you for some time if you want to get full 5 stacks. Also with choke bomb, I am able to run-> 4-> blink step into the enemy.
2. Have you tried using just RMB/F when you have Fighting spirit buff on? The crit rate would be close to 100 and practically guaranteed DS on hit. If you pair X smoke bomb and shadow drain-> unstealth, you wouldn't have much chi problems also.
Overall, I'm just curious on your opinion with Choke bomb, Shadow drain for chi regen and unstealth, and pure RB/F spam during fighting spirit.
For reference, here's my opening combo:
Windwalk-> 4-> RMB (Blink step stealth)->2-> 4-> RMB/LMB/F combo to next 5 stack-> Tab->1(Shadow drain for focus recovery)-> LB(Spinal tab to exit stealth and lower shadow drain cd)-> RMB/LMB/F combo til bns gold farmer-> V (Fighting spirit/poison reset)-> 1(You can try for 4 also since it's close to getting off CD, but it's a tight timing)-> LMB->4->X-> RB/F (Dont need to LMB since your crit rate is 95-99% and you have chi regen from X and Shadow Drain)