It's always words with you
Your thread is moral. As are your ethics.
Both can be both ethical and moral because there's not enough information there as to
why the man does not mean what he says.
For the first half:
One can, by recognizing the act as righteous, commit the act as a moral deed in the sense that one can bless with intention of the inherent righteousness of a blessing doing good for one who receives the blessing, but ultimately not mean the blessing that one gives. As far as ethics, it is ethical in the sense that one should always commit moral acts as a code of conduct whether they recognize the inherent righteousness of the act or not.
For the second half:
It is moral for one to speak one's mind in the vein of honesty and also moral to recognize and repent when that honesty has a potential to offend. The sensation of guilt does not mandate an ethical response to the sensation of guilt, but in light of
why one would feel guilty for cursing, it is ethical to repent.