Take squad members with AoE powers, and save the explosive canisters for when there are multiples. The ship comes when you've killed a certain amount of Varren, so once it gets there, be ready to click and high tail it. I did it with an Infiltrator myself, but I brought squad members like Zaeed with his Inferno Grenade and I think either Jack (Shockwave) or maybe it was Samara/Thane/Miranda with AoE Reave/Warp. Grunt/Garrus with Concussion or Samara with Throw helps as well since they can knock the Varren on their butts.
Adept not good for insanity? You're joking, right? Aside from the Sentinel and Solider, Adept is easily the best class for insanity. Disabling powers like throw, shockwave and singularity are invaluable. And yes, I'm referring to ME2