Without going to deep, cause I'm in the work now, and IMHO. I think it will be very difficult Chavez make a big clash with the USA. The reason is simple, he will stay on power while have enogh money and the major buyer of Venezuela oil is just the USA. Start a conflict with Colombia will put him in direct collision route with USA too. Maybe going over Guiana is an option, but it will probably rise up the opinion of the rest of the world against him, and some kind of embargoes from UN. The great risk in this case is he's anoying someone until this someone start a conflict, wich could legimate his intentions.
But, IMHO again, the greatest risk is the bunch of pseudo-leaders that are rulling the SA countries today and look with shiny eyes for his bloat. At last, it's much more easy to put the guilty of social problems in the rich countries than recognizes the self incompetence.