Mass Effect 2 on first playthrough – Part 1

Beat Mass Effect 2 recently and managed to get all but 3 achievements: Insanity – Beat the game on Insanity difficulty; Overload Specialist – Use Overload to destroy a shield 25 times (only did this 22 times); Warp Specialist – Use Warp to destroy a Barrier 25 times (only did this a few times). I probably could have gotten Overload and Warp, but didn’t realize that you actually had to...