Unfortunately, the hunter starts off kind of boned as they are the only class without a void based subclass. Disclaimer- I am by no means an authoritative word on pvp, in fact, I'm pretty awful, so take my advice with a grain of salt.
Hang on to your void fusion rifle or spend marks to get a better void FR. Reason for that and not a void rocket launcher or LMG is the heavy ammo is few and far between as to whether you would be able to pick some up, whereas you will always have special ammo in the crucible.
Play the Control map type. With Control, you will always have an idea of where you could find enemy players (they'll be heading to one of the three points) Salvage may also be a viable play list, however, there are fewer players, so I just mentioned Control as being more time efficient due to a greater chance of more kills per match than with Salvage.
Buddy system- try to stick with at least one other player and focus fire on whatever target they're shooting at. Not sure if you get points for assists, or kills only.
Guard flag or choke points and let the enemy come to you before firing FR volley. I think at longer distances, it will be outgunned by AR and SR because the recoil forces the weapon upward which will diminish the number of hits. You want them close so the whole volley can hit center mast and travel upward, ending at the helm.
Having said all that, I've not completed the Thorn bounty myself so it is very possible I'm talking out of my ass.
