You're working too hard. - Even if you're a paragon, you'd have to be stupid not to take this chance to even the odds in your favor.
You talk too much. - Same as above. And it's true, the stupid krogan talks too much.
Renegade interrupt in Miranda's mission - Again, Shepard's a soldier, if all diplomacy fails, don't be surprised when he/she plays dirty to win.
Headbutt Uvenk - These are krogan you're dealing with, so use force to make a point. Plus, it's funny as hell.
Interrogating Elias Kelham - Some days you don't wanna sweet talk the bad guy, sometimes you want to give some "extra incentive" to spill their guts.
Shepard's angry responses after Collector ship Mission - I don't care if the trap was necessary, no one likes being set up like that.