The personhood question IS the argument of pro-choice individuals. You can try to spin it to what you did, but it's inaccurate and misleading. A fetus is a group of cells that becomes a human organism and person eventually. Pro-choice individuals are not saying that "a class of human beings should not have protection..." They're saying that these cells are not people and as it is dependent on already living people in order to become a person, the host should have a say as to whether or not it continues to grow, at least until it is able to live without the host.
This is what I mean by your misunderstanding of the position. A difference of opinion among pro-choicers doesn't make it arbitrary. Most pro-choicers believe it is just tissue at least until after embryogenesis and that as long as it is dependent on the uterus and bodily mechanisms of someone else to survive, it is not a person. Until then, it is literally putting someone else at risk just to stay alive and the person whose life is at risk should get to call the shots.
So then you're also outraged about these laws? At least on that we can agree.
This is quite disingenuous, a "group of cells"? This is the sort of classification that would not pass muster in freshman level Logic course. You and I are groups of cells, my dog is a group of cells, the plant at my kitchen table is a group of cells; this phrasing completely ignores the relevant ethical import. Furthermore, a fetus does not "become" a human organism. Again, from a strictly scientific perspective the embryo/fetus is a wholly distinct member of the species
Homo Sapiens, this is not "spin", this is simply a scientific fact that once again is accepted by virtually all pro-choice philosophers. The argument made by people like Judith Jarvis Thompson in her violinist example is precisely that the embryo/fetus ARE human beings and "people", but that the mothers rights universally overrides this fact.
Once again, this is a simple re-statement of my original framing of the pro-choice position, which you are loathe to own, which is that some human beings (in this case the pre-born child), loses the inviolability that characterizes the rest of human beings. You may think this reality is justified on some other rationale (personhood, maternal autonomy, etc.), but that doesn't change the fact that the original formulation I laid out holds.
Regarding you 2nd to last paragraph, I am not sure if you are referring to the average Twitter user who is pro-choice, or the actual experts on this topic, but I cannot name a single pro-choice scholar who thinks that the fetus is "just tissue", again you and I are "just tissue" as well, this doesn't tell us anything about the relevant ethics. Again, we aren't debating abortion as a whole here, simply my characterization with which you took issue earlier. To refute this, you will need to show that even in a strictly biological sense, the fetus/embryo are not distinct human organisms - again, as I laid out this would put you at odds not only with virtually all pro-choice philosophers, but with the current consensus in human embryology.
To end on a positive note, yes I agree with you on the last point of ectopic pregnancy or really any time the mother's life is in jeopardy, and so do most civilians and pro-life scholars btw (despite the occasional ignorant politician who may say otherwise).