You raise interesting issues.
With regard to women's ordination, of course, the Church teaches that you can say the words of ordination over a woman, and just nothing will happen. You don't have proper matter, you need a baptized man, not a woman.
With regard to permitting the already-ordained to marry, the Church does permit men previously ordained to marry, and they are validly married. It actually happens. Of course, the Church requires laicization first, but even the loss of the clerical state does not undo the ontological effects of ordination. The man, though having rejoined the laity, is still a priest, even if he may not licitly call himself one anymore.
Yet, I think that the mind of the Church is not that this is like the discipline of not permitting married men generally to become priests.
There are others who could better speak to the theology involved with this, but I think that what the Church is saying is that the discipline of ordaining only celibate men is a good one, but not an absolute moral necessity, while the practice of barring clerics from marrying post-ordination is a matter of moral necessity, even if it is not a matter of ontological impossibility.
So, although it might be that a cleric might validly marry, it would be like a man who steals or commits adultery. It's possible, but intrinsically evil.
sitetest
Excellent discussion, sitetest. The distinction between what is “allowed or not allowed” and what is “possible or impossible” is often lost.