I agree with most everything you posted, and it may seem that I'm picking a nit. However, in #27, you said:
“But it is legitimate to remove the fetus when it is an ectopic pregnancy, because leaving it will 100% kill the mother, and there is 0% chance that the child will survive.”
The “because leaving it will...” is problematic. The reason why it's licit isn't because the ectopic pregnancy will definitely kill the mother and there is no chance for survival of the unborn child. The reason why it's licit is because there is an underlying medical problem - the inflammation or infection of the fallopian tube - that is life-threatening and for which there is a medical treatment that is not direct, intentional abortion.
That's why it's possible to say that the death of the child is an indirect, unintentional effect.
With a direct, intentional abortion, what is being “treated," what is the “disease” being “cured” is the baby.
That's all.
sitetest
As I understrand it, this is a sitution that can develop fairly early, like maybe 12th week of pregnancy or so, for which the prognosis is very, very poor for the mother. Part of the moral dilemma is that nobody is quite sure what causes it, but it might be caused by abnormal function of the placenta.
Now, as I undersand it, the placenta is a shared, feto-maternal organ composed of cells and tissues of both the mother and the baby. The part that faces toward the baby develops (like the umbilical cord and the anmionic membrane) from the baby's blastocyst: in other words, it is one of the external organs of the baby. The part that faces the mother's uterine wall develops from the mother's endometrial cells: it's part of the internal develoment of her pregnant uterus.
Here's the thing: the fetal placenta and the maternal placenta, are intricately intertwined. Zillions of tiny maternal spiral arteries mesh together with the fetal villi, kinda like velcro hooks and loops, keeping the villi bathed in maternal blood, for essential nutrient and gas exchange.
OK, bottom line, say acute pulmonary hypertension is indeed caused by a placental disorder. If the placenta were the mother's organ, it would clearly be OK to remove this malfunctioning organ in order to save the mother's life. If it's the baby's organ, then you can't attack the placenta (e.g. remove it) because you're attacking the baby himself.
Whether you prematurely deliver the baby from the womb at this stage or not, it has no effect whatsoever on his survivability. Either way, his survivability is zero. But if you remove baby and placenta, the baby dies (as he would anyway) but the mother's hypertension rapidly resolves and she regains normal heart function. It saves her life.
Keep in mind that there's a lot they don't know about exactly how this works.
I have read that reptable Catholic prolife ethicists are divided over this one: can you remove the baby and placenta from the womb at 12, 13, 14 weeks or not?
I have my own opinion, but I'd like to hear yours.