There seems to be an assumption here that empathy leads to morality. Sometimes, at least, empathy leads to being jerked around by the stupid goals of others instead of pursuing your own stupid goals, and in this case it's not all that likely to lead to something fitting any plausible definition of "moral behavior". Chogyam Trungpa called this "idiot compassion".
Thus it's important to distinguish caring about humanity as a whole from caring about individual humans. I read some of the links in the OP and did not see this distinction mentioned.
There seems to be an assumption here that empathy leads to morality. Sometimes, at least, empathy leads to being jerked around by the stupid goals of others instead of pursuing your own stupid goals, and in this case it's not all that likely to lead to something fitting any plausible definition of "moral behavior".
Indeed; see http://lesswrong.com/lw/7xr/not_by_empathy_alone/ and in particular the should we section.
Moral training, education and self-cultivation are also a common theme in virtue ethics traditions.
I'm curious: if you're a person interested in "benevolence training", why do you want to have more benevolence or empathy for others? I generally want to be less empathetic, and I'd love to be convinced that I'm wrong.
I attended a talk by Julian Savulescu today, and I'm typing up some notes for a discussion-level post.
In offline conversations, several Less Wrongers have expressed interest in 'benevolence training'. For those who are interested, here's a head start in the research...
The technical term for this is 'moral enhancement.' The key name here is Thomas Douglas, who wrote his Ph.D. thesis on the topic, and continues to write papers on the subject. A recent overview is his paper Moral Enhancement (2008), reprinted in Enhancing Human Capacities (2011). That chapter is followed by another chapter on the subject, by Persson and Julian Savulescu, who have written other papers on the subject.
Here is a Guardian article on moral enhancement, and here is an interview on the subject for Philosophy Bites.
Some other key terms on the subject are prosocial development and empathy education.
Edit 7/29/2012: Also see Molly Crocket on moral enhancement.