For the Berserker i would advice you NOT to use "Rage Retaliation" it SOUNDS really good, but the damage you deal is REALLY low and it does not go off as often as you would like to make it worth any skill-points at all.
I have done some big sample testings on Rage Retaliation to determine myself it if was worth 15 points or not, vs. all T1 bosses and it was clearly not worth it when i tested it, and no change has been made since then, so its still the same: Not worth any points.
I have made some testings of StormClaw as well with 15 points, it is a rather useless skill for level 100 stuff.
For a Level 100 Build:
You actually WANT 15 in Red Wolf as that can proc every 0.1 second it seems, so adds a lot of damage (Works vs. Single Target as well, awesome skill)
You WANT 15 Points in Battle Standard, adds +40% Dodge and some mana regeneration at 15 points.
You want 15 points in Blood Hunger as it procs even from Wolfpack, and it also procs from Shadowburst.
You want 15 points in Howl (Increases damage taken by a LOT, definitely worth 15 points)
At level 100, you dont die from small hits, its always big hits that kills you, so to minimize the risk of death you want 15 points in Blood Hunger so you can use Shadow Burst to heal up right away after you take a 20k hit to the face.
If you want to do Darkness Falls bosses (T1/T1.5 items), i advice you to get 200 Vitality (Vitality is better than pure HP in Darkness Falls when you get the Mythical Skulls that adds vitality etc), Vitality has an upscaling curve, so each point is worth more HP, starts out at 10 per point and ends somewhere around 27-28 per point near 1000.