I am by no means a bard expert so take my boredom-induced advice with a grain of salt, but... As far as I know, you are supposed to hit up Bloodletter immediately after Straight Shot and only then proceed into your poisons, as if you do it in the order you're doing it, you're risking missing out on an internal timer DoT -tick and thus a potential Bloodletter proc right off the bat.

Apart from that, I'd say wait for the actual legit bard mains' responses, but yeah, for barding: buff order (IR, B4B, etc. etc.) and how vigilantly you use your oGCDs with your GCDs is what matters. You also didn't mention anything about Repelling Shot or the like, which should be also used for that little extra DPS (as well as Blunt Arrow when not needed for silence).