It would be more accurate to classify the default ME1 Shepard as a psycho killer, rather than Renegade. Everyone who could possibly die will die for the default Shepard. This includes major characters like the Council and Wrex, as well as minor characters such as Gianna Parasini, the Rachni Queen, Fist, Helena Blake etc. A whole bunch of minor characters make cameos in ME2 if they survive the first game.
On the whole, I'd say ME2 is more enjoyable with an imported save.