I have come to find that DPB is kind of still rubbish, the only time it really shines is when there is 3 vamps on the target which means DPB will hit 3 times and will hit at the higher %. But being the 1 sec cast (same as combo shot) that CS will still pull out more damage in that 1 sec whether any of the 3 hits crit or not. Compared to using DPB when there is only 1 active vamp on target.
If you are using DIYCE, use DPB manually when u see target has 2 or more vamp debuffs. Otherwise I feel you are losing too much DPS.
But for me at the moment, on DIYCE
WS
PA
CS
RS
Shot
Vamp
DPB (manual, not in diyce; only cast when as I mentioned)
And obviously autoshot/sapping is activated as soon as fight begins, sapping before anything else to help the whole parties burn as rogues will begin dps much sooner than scouts.
And with exploiting shot, to try so hard for that crit during a full burn is just pure luck so don't rely it on. It may or may not happen at all during a quick boss fight so don't rely on it by using shot too much, shots damage sucks even compared to vamp (lol fail)