Objections and Disagreements, Part I
This is a factor we are totally unsure about. Personally, I highly doubt vampires lose their souls. I can't imagine any of the Cullens, especially Edward, not having a soul. Of course, whenever I think of this subject, Dementors pop into my mind.
We'll just have to wait and see.
You say that one reason Bella would regret her decision to become a vampire is because she'll be losing a whole future, such as having children. Yes, you're right. Adopting vampires as kids is not the same. You can't watch them grow and learn. But Bella lost this future since the day she fell in love with Edward. Even if she stayed human, it would be impossible for her to have children. Well, not impossible. But she would never make the sacrifice necessary to do so. To have a child requires one human female and one human (or werewolf) male (not going into details). Edward is not human, and the chances of him becoming one are very slim. Bella cannot have a child with Edward. She'd have to 'be with' another man to have one. She'd never do that to Edward. She'd never want to. Yeah, sure, she could change her mind and pick Jacob. But at what cost? Jacob could leave her easily because of imprinting, and that would hurt Bella a lot. Even if Jacob didn't imprint on someone else, Bella would never leave Edward. It would hurt her too much to leave him. Sure, she might heal eventually, but it would hurt at first. I highly doubt that Bella would put herself through that.
Bella's chances of having kids were gone when she first saw Edward in the cafeteria.
You say that Bella is taking advantage of Edward's love for her by making him do something that he doesn't want to do. You're right to a point. Edward doesn't want to bite her because it risks her soul, and he thinks he's being selfish because he DOES want her to be a vampire. He wants to be with her for eternity just as much as much as she does with him.
Bella does think she is taking advantage of his love for her, and she hates herself for being selfish. This is where Edward and Bella must overcome the choice that all relationships like theirs must face; the choice between what you want and what your true love wants. The choice between love and lust. This is also where compromise comes in, because if both people in a couple are trying to make the other happy, you get problems (Example: "I'll watch whatever you want to watch." "I want to watch whatever you want to watch." "But I want to watch whatever you want to watch." Etc). Edward and Bella have made compromises. Edward will bite Bella, risking her soul, in return for her hand in marriage. Stephenie Meyer has confirmed many times that Edward and Bella WILL get married in Breaking Dawn. A relationship can only work if both sides help to make it work. So if Bella fulfills her side of the bargain (which Stephenie Meyer says she will) then there is a very high chance that Edward will do the same. Sorry Esme, but it's not looking so good.
You say it would not be natural for Bella to be a vampire. I agree, it's not natural. Human is her true nature. Same for Edward, human WAS his nature also. But, again, the chances of him returning to that state are slim. His body has changed drastically and he has been a vampire for a long time. The chances of him becoming a human are probably 8, 670,080 to 1 (made up number). As for Bella, she's really got no choice. Remember the Volturi? Bella's not going to let Edward risk his life protecting her while she stays human.
You say that Bella will be unhappy because she will never see her human family and friends again. I totally agree! The loss of a loved one is a terrible thing to go through. But it's unavoidable. Whether she was vampire or human she'd move out and/or they would die eventually. We have to let go of them sometime. Jacob is trickier. Yeah, he's not aging, but he's going to have to sometime. Whether human or vampire, her love for Jacob will always leave a scar. But she's made her choice: Edward. She can't live without him. But she'll always love Jacob. And she'll have to deal with the consequences of that love. It's painful, but unavoidable. Because he left, Edward has accidentally doomed Bella to a life of pain. No matter what her choice is, she will have to suffer. Sad, but true.