What problems does it face, either as a classification of Buddhism or as meta ethical theory in general?
Another approach [to how to classify Buddhist ethics] is aretaic consequentialism, an indirect form of consequentialism in which the primary objects of evaluation are character traits, not actions or rules. This theory tells us to develop in ourselves those states of character which are conducive to the happiness of sentient beings. (See Siderits 2007, 292–93) This elegant interpretation explains why Buddhist texts so often focus on character traits, but it also retains a hedonist view of well-being. It allows us to interpret instructions on moral discipline not as inflexible rules, but as advice about what traits of character to cultivate.
I think this classification suggests that at least conventionally speaking only our own virtue (unlike e.g. "character consequentialism", working for welfare - virtue and happiness - in general) is worked for, and this enables everyone's (our own included) happiness.
Bodhisattvas are typically versed in "merit transference", which may involve an impersonal virtue as its motor
Santideva is now depersonalizing not only his ends, but his own state of being. The transference of merit he envisions involves conceiving of his own virtue not as a state pertaining to him, but as a more general feature of the moral universe, and hence his own experience of himself, as of generosity, is transformed through the cultivation of engaged bodhicitta.
My point being that, while the absence of a substantial "self" does not mean we are not better placed to act for our own virtue and happiness, there's just no other reason to cultivate either for myself.
prudential concern is compatible with the doctrine of no self
Is it anti-Buddhist and egoistic, as some commentators suppose, to always cultivate our own virtue?
Depends on 'skilful means'.
I'm fairly sure that sometimes we should take actions that will make us unhappy, but I should never try to be vicious; I should always be virtuous.
Act as a virtuous person would act in your situation.
If then (prudential) virtuous actions always make us more virtuous, we should always be making ourselves more virtuous (whether or not we can at times add more to the virtue of others than ourselves).
I do not know if "aretaic consequentialism" entails this.