"Chavez has compounded his country's loses by selling very cheap oil to Cuba."
Yep no doubt profit isn't his goal as the transaction involved Cuba sending a ton of Doctors to Venezuela's poorest areas where no health care system existed.
Chavez is subsidizing Cuba to the tune of $2 billion per year, in cheap oil and in cash. If all the Venezuelans are getting out of this is 13,000 doctors (one figure I saw), then that's over $150,000 per year per doctor. Considering the standard of living in Venezuela, I'm sure they could train and hire Venezuelan doctors for a fraction of the price.
Your point about Chavez making friends in Latin America is well taken (though Mexico might point out that not all Latin Americans think much of Chavez). One example of how Chavez wins friends is the case of Argentina, where Chavez has spent about a billion dollars on bad Argentinean government bonds to support Kirchner. Kirchner has recently asked Chavez to spent a few billion more in exchange for political support (such as that demonstrated during the Conference of the Americas). Once again, the Venezuelan people receive nothing for their billions spent.