Don't just mangle spam, use a case sequence to get rake in there, its TONS of damage + combo point for cheap energy cost. Also gear / gem full agi for best return on stats. You're right opening with a 2pt Savage Roar is fine on trash, and I even open boss fights like this. Mangle, Rake, SR, Tiger's Fury, Mangle, Mangle/Rake to 5pt, Rip, Mangle/Rake to 5pt SR. The idea being you don't want SR to fall off, or Rip, or Rake/Mangle. Tiger's Fury has a short CD and if you're speced to get 60 energy from it, it's a great energy pot on a short CD + extra damage.