Brutal Scoundrel Rogues are the purest damage-dealers a Rogue can be, so optimize with that in mind. Rattling Attacks have nothing to do with Charisma, you just need to be trained in Intimidate to get their effect. Disheartening Strike might be worthwhile if you go Eladrin and pick up Heavy Blade Opportunity to rattle enemies that draw OA's from you. Beyond that, I prefer Riposte Strike for Brutal Scoundrels, and then your favorite of Deft Strike or Piercing Strike. Being attacked isn't a bad thing, the enemy usually takes a -2 on the roll (for being marked) and generally suffers some nasty effects (radiant damage, your riposte attack, or even an immediate interrupt attack).
Anyway, for PHB races just about anyone can be a good Rogue. The best for Brutal Scoundrel rogues specifically are Humans, Elves, and Eladrin. If there isn't an Elf in your party yet then pick one for the Perception aura. For your stats, pick a dumpstat. Better yet, I'll pick it for you: Int. Int goes to 8, Constitution goes to 12 for the extra Surge, you lose precisely nothing. For your feats, Backstabber is good, Skill Focus is bad, Quick Draw and Weapon Proficiency are iffy. I say drop Skill Focus and Quick Draw for Two-Fisted Shooter and a racial feat (Elf: Sneaky Accuracy, Human: Action Surge) or Brutal Wound (because Heroic Eladrin feats aren't good for Rogues).
When it comes to Paragon Paths, then pretty much all of them are about the same for Rogues. For raw damage output, I like the Death Dealer. It's especially good with Humans that like using Action Points. If you want to stick to PHB stuff, Shadow Assassin is still pretty impressive. If you're allowed FR material, Ghost of Eventide is exactly what you want for this character.
As for party makeup overall, I disagree with PI's assessment. Once you get the core 4, I prefer adding strikers all the way. If you need more healing, get some healing belts. If you need more Marking, get the Fighter to take more Close attacks. As long as the Leader is well-protected and another party member has just one healing ability for a backup (even if it's just a basic healing potion) then you should have more than enough healing to get you through any encounter.
For items, I'm not sure I'm a fan of Deathcut armor at all. Daily powers that deal a little damage are pretty blah. You were given some loose gold with which to buy more items, right? Buy plain +1 Hide armor. The good stuff comes later on. For your level 5 item, you could do worse than a Flaming Hand Crossbow. The power will almost always deal more damage than your Deathcut Armor's power, and then there's each failed save. Whats more, since it's Ongoing Fire damage it won't interfere with ongoing damage from your Rogue powers.
