Well thats all well and good. But from what I see, being tainted by Dark Side, is like being addicted to drugs. Just like the addict does everything he can to get the next hit, so the Dark Sider will do as much as he can to get the next hit of the Dark Side's power. If there is choice where a matter could be resolved peacefully, or violently, and peacefully would be better, the Dark Sider will often choose violently, because it is then he feels the Dark Side of the Force.
The best of the Sith are the ones who can best control their addiction. The only one who seems to do this really well is Palpatine, but thats maybe because he's been doing it for so long.