Questions for you hunters
In a way, you are over-complicating it. In practice, it might be more complicated.
First, if you like BM, our top hunter is BM (my main is prot pally or I THINK I could take him on my SV hunter, lol). BM no longer has to hang it's head raiding. Personally, I like to play with all specs of my toons though so here goes:
Opening for me is hunters mark pre-pull, serpent sting (you forgot above but I hope was an oversight because it's important) explosive shot (first so the cd is back sooner), black arrow, rapid fire (on bosses).
After that, you always spam cobra shot (CS) which refreshes serpent sting. The only time you stop spamming cobra shot is when black arrow (BA) or explosive shot (ES) come off cd.
Lock and load should be ES, CS, ES, CS, ES.
One CS is enough time for the ES ticks to tick all the way out. The last ES is because the cd on ES is guaranteed to be up by the end of the proc cycle. Also, you should gain a ton of focus during this. At first, just live with it. Once you get comfortable with it, try to not cap by using kill command in there. Don't use arcane shot ever. You don't want it consuming an LnL proc and you should not be capping out almost any other time.
"he doens't need healing, he doesn't need healing, he doesn't nee-WHAOSHIT!wtf was that man!". Please stop leaning on TDR. -Teng