but can an ordination be valid if the person ordained has no faith?Aquinas indicates a lack of reason does not invalidate an ordination. Similarly both the sinful man and the wicked man validly receive orders, though it can be sinful for them to do so. I don’t find anything directly by him on lack of faith, but this seems to be pretty much the same thing as the discussion on the wicked man, so I image that the faithless man would receive unworthily, though validly.
I’m not sure what you mean, that it is not always the case that the words of Consecration are the form, or that the words are always properly said."Valid form is very brief, it is simply the words of Consecration,..."BTW, that is what I thought too. It is evidently not always the case.
I have seen the words mangled invalidating the Consecration more often than I have seen invalid matter used, but it is still pretty rare in those Masses I have been too. I walk out when it happens.
patent +AMDG