I hate the expression TLDR but this thread is really very long and I'm pretty sure it's just fighting back and forth after the first few pages, which i did read. I just wanted to toss in my idea on the topic the best way I know how: with "fun" comparisons and metaphors.
1. If somebody crashes their car into a tree, and totals the car, should they be allowed to drive again?
Yes. Just because they fucked up once, does not mean they are too immature to control a vehicle.
(Similarly, if someone has an abortion, it doesn't mean they are too immature to have sex. It's called "learning from mistakes" and it happens to a lot of people. Even Christians, Republicans, and men!)
2. If somebody is a vegetable in a hospital bed, with no brain function whatsoever, is it wrong to pull the plug?
No. Hardware with no software is useless and a body with no life is not a person.
(Similarly, a fetus with a heartbeat is human hardware, but the OS doesn't boot till it's pushed out of the baby factory. Unless you remember being in the womb. I sure as fuck don't.)
3. As a man, do I have any right to tell women they can use maxi pads but cannot use tampons?
No. I have no right to tell a woman what to do with her body, nor should I act like I personally know what it's like to experience gender-specific bodily functions that only happen to the opposite gender.
(This relates more to the fact that most of the people who debate about abortion and make laws pertaining to the subject are old, rich, white, male, and are not necessarily upstanding citizens themselves. It's all about the "pro-family" public view.)
You can tell I'm not against abortion by any means, and I do think Pro Choice is a great way to describe the view, albeit a little vague.