Is the heterotroph hypothesis universally accepted?
I would say the the topic is still very much under debate. This paper by Ferry and House (2006) briefly review the heterotrophic vs chemoautotrophic hypotheses. They include citations from proponents of each hypothesis. Interestingly, Ferry and House propose an "energy conservation" hypothesis that attempts to merge ideas from the other two hypotheses.  Overall, much work remains to be accomplished in this field before we have a clear understanding of the origins of life.

Literature Cited

Ferry, J.G. and C.H. House. 2006. The stepwise evolution of early life driven by energy conservation. Molecular Biology and Evolution 23: 1286-1292.