Work for what? What is it you want to accomplish, and is this build for PVE or PVP?
I'm guessing it is for PVP since you say you are new to ranger builds thus making you new at playing ranger.
Apply Poison is a preparation skill, Melandru's Arrows is a preparation skill, and Read the Wind is also a preparation skill. You CANNOT use them at the same time. This makes the build very ineffective.
It seems like you want to create a health degeneration build. Observing the skills you have mentioned, you can use Apply Poison, Hunter's shot, and also Conjure Phantasm very well together to degenerate health. Epidemic, if I am correct, will TRANSFER all these conditions that you have set upon your enemy to any adjacent enemies. Transfer saying, that he will no longer have those conditions and you need to reapply them to your target.
Alright, so we have
-Hunter's Shot. (Bow Attack)
-Poison Arrow. (Preparation Skill)
-Conjure Phantasm. (Hex Spell)
-Epidemic (Spell)
I would suggest getting 2-3 skills to defend yourself such as Troll Unguent, which you stated, for heath regen (or healing spring but i dont recommend it) and a skill like Whirling Defense, Lighting Reflexes, or Dryders Defense, to protect you from most harm for a few seconds. Throw Dirt works well on warriors and rangers, people fighting with melee weapons or a bow.
Pin Down or Cripple {E} would be cool, because you could inflict another condition. Think of this.
-You could apply poison, then cripple them, while they move shoot hunters shot, conjure phantasm when you have enough energy, then move on to the next enemy, fire away your poison arrows with a hunters shot, C.P. and so on.
Or you could go ahead and use epidemic, I think it would work, but be sure that the enemies are close together (which is rare) and reapply conditions on the target foe.
Bringing an interrupting skill like Distracting Shot or Savage Shot could help a lot too.
For random PVP, get skills to defend yourself, along with Resurrection Signet, because you never know if you will have a monk ally.
For tombs, talk with your teammates, and ask them if you will need self healing and protection.
For PVE, I would suggest always bringing defensive skills.