Humanoids fights uses the normal rules, it is only monsters that uses monster attacks. The goblin in the scenario is probably pretty standard for a goblin, he will go down fairly easily. Also something to think about is that none of the pregens have any heroic abilities, they are starting characters (with a bit higher than normal attributes perhaps.
Regarding 'dirty', Tomas have said that they will most likely change that to something else.
How about "Sullied". It potentially has both physical and social connotations so it would leave a lot of room for player description.