Streamline can be dropped for (Primed) Flow. Arcane Energize is heavily recommended if doing so.
Alternatively, Rage/[Hunter Adrenaline] can be used for energy sustain instead of Streamline, with Primed Flow replacing Constitution or Stretch.

Stretch can be replaced with Hearty Nourishment or Augur Secrets/Message if you are comfortable with the base range on his abilities.

Regurgitate is the weakest ability in his kit as Feast does more or less the same but better.
Roar/Expedite Suffering replaces it as both help Feast

Memes Jack:
Theorem Demulcent, when triggered by Residual Viremia, will buff the damage of the Toxin procs from Feast.