Here's the following I use for my Surv Hunter right now. I've only tested it on the targeting dummies but not in the field yet, let me know what you think if you do try it out as well.

Spam button
/castsequence reset=2 Serpent Sting, null (I use the Mark for Death glyph so no need for Hunter's Mark)
/click (whatever your hotbar button is)

Boom Boom button
/cast Cobra Shot
/cast Explosive Shot
/cast Arcane Shot
/cast Black Arrow
/cast Kill Shot
Make sure you put Cobra Shot/Steady Shot first in the list or it will get hung up on the other spells if it has a cooldown. I don't cast CS as much with this one as I did with my previous setup, mostly when I don't have Focus for my other spells or no free procs to cast from LnL or TotH.

I haven't tried with Arcane Shot first, but I can later to see if that makes any difference. Judging by what is above, I'm betting this is the reason it locks up. Try to put Cobra Shot or Steady Shot first on the list. Only thing I don't like about it like this, is it does not always pop off ES when I have Lock and Load up, so those get wasted sometimes, for this you can set on a separate button and manually press along with this button. I took on Thrill of the Hunt talent so that my Focus bar stays above or around 50% most of the fight, leaving enough Focus to cast Black Arrow each cooldown.

This does seem to pop off Arcane Shot every time it comes up as a free focus dump from that talent. Black Arrow hardly got used with the Dire Beast talent for me, that however mixed into this macro did stay up every cooldown.

As I don't PvP, I did not put Widow Shot in there, but can be tested to see if it works also, with it also, might want to put it after Serpent Sting on the first macro before the ,null or apply it seperately when needed.