It's a bit different this time around from what I understood. Each battle.net account will need a unique license, like World of Warcraft, so it's entirely possible that you'll only have one identity per CD key. Maybe they'd let you create multiple profiles to have multiple names, but if one of their goals is to stop lowbie stomping in rated matches, then that makes the inclusion of such a feature unlikely.

"They sailed away without accomplishing their purpose" is another way to write that sentence. In other words, their purpose effected nothing. Nothing came of what they set out to do. It didn't produce anything. I'm not sure how many times I can redundantly state its meaning ;)

I think "affecting" is more appropriate to use. Instead of "it" being the primary cause/responsible for the crime scene, it would be responsible for altering it/contaminating it.