Do Chechens tend to be terrorists, gangsters, or freedom fighters struggling for national liberation? 

How about: All three?

The skill sets of terrorists, gangsters, and freedom fighters overlap to a fair degree, and in the real world, we see many examples of this, with Chechens being perhaps the most extraordinary examples on a per capita basis. 

There has been much psychoanalyzing in the press of the alienation of the Bomb Brothers. Perhaps the best explanation of their anomie is that there just weren't enough fellow Chechens in America yet to form a proper Chechen Mafia, so they had to act out their Checheny impulses on their own. 

Since the answer to all problems caused by immigration is to increase immigration, I look forward to essays explaining that the way to keep Chechens in America from blowing up marathons is to import more Chechens so they can have the weight of numbers to take over, say, pimping in the New England area or some other non-terroristic pastime appropriate to their cultural predilections.