Talents:

1. Perfect Aim and Scented Tincture are both useless. Inner Beast is the best ability for Greymane, so Choosing between Wolfheart and Viciousness is mandatory. Viciousness will help keep Inner Beast up if you have trouble staying on target and hitting with auto attacks, however if you can stay on target, Wolfheart will allow you to transition between fights with less downtime. The ultimate goal is to never be in a fight without Inner Beast, so take it on your self to determine what better fits your ability. Easier uptime, or less downtime between fights?

2. Draught Overflow is useless for this build. Insatiable is nice, but I find myself low on HP more than mana, so I usually return before ever running out. It's a good choice if you're laning with a healer. Thick Skin is good against high hitting basic attack characters, otherwise Eyes in the Dark appears to be the most useful.

3. Incendiary Elixir offers strong, immediate opening burst damage on a single target. Wizened Duelist is the stronger talent, but at least while I'm learning this character, I can't justify it quite yet. Quicksilver Bullets allows for a better poke range, but I still can't take it over Incendiary Elixir.

4. I've done a few games with both talents, I can't justify using Marked for the Kill. I think the damage from Go for the Throat, even when used on a single target without securing a kill with it; has better output than Marked. Marked for the Kill's Vulnerability does, however, make it very easy to drop tanky classes, particularly when they're being focused by more than one person.

5. This is one of the more difficult choices. On the Prowl is great for securing kills against fleeing targets. I don't feel like Unfettered Assault's range increase justifies the cooldown. Darkflight and Disengage are used so seldomly that I don't feel Running Wild is a great choice. It's a flip of the coin between Visceral Attacks and On the Prowl, personally.

6. I like Relentless Predator a lot as a survivability talent. I would pick this against heavy CC, heavy damage teams. I would however pick Alpha Killer against tanky teams. Concentrated Blast is not useful enough to justify giving up these other talents. I'm still struggling to see if I like Alpha Killer or Executioner more. Edit: I find Executioner to be the most useful for damage, if you've got enough CC on your team. It's really a notable difference.

7. I feel that Unleashed] is a very niche ability. It could be a team fight ender, if used correctly, otherwise I would pass on it. [[Tooth and Claw is my premier choice because this is primarily a worgen form build, however Hunter's Blunderbuss is a safe way to do some AoE damage in fights.