Two meanings will appear. First, the Romantic Idea of the "itinerant worker" or "tramp" in American Culture. http://www.press.uchicago.edu/Misc/Chicago/143783in.html Another meaning might be something like the Romance between a homeless man and woman, or between people who have no property and no structure in their life.

I don't know what it means, but knowing something of that game, it's undoubtedly offensive. Maybe ask your question here: http://boardgamegeek.com/thread/696546/references-you-might-not-have-gotten

I am not sure what the phrase is supposed to mean, but a Hobo is a homeless person.

Vagrant dalliance?