Re: About MJ and the men...
Yes I think Mary Jane is a person who very much cares about her own feeling a lot. She is highly guarded about her own feelings and will run off if something isn't catering well to her feelings. She often falls back on the abused accuse quite a lot it seems (well if KD's commentary is anything to go by.) And depending on how personal the issue of abuse is to you, might depend on how much understanding you have of the character.
I think regarding the relationship, what I will say is that it was at least realistic. Realistic in the sense it mirrors many other relationships out there, particularly ones where one of them has a greater significance/ importance/ fame/ destiny than the other one. There is a touch of jealousy there and a touch of 'Is this how it will always be, you getting all the glory and attention and me just picking up the pieces?'
Of course she was written quite badly in SM3. All I can say in her defense is that you really have no idea how her character behaved in-between SM2 and 3. You don't know if she was the perfect, supportive, obedient, cheerful housewife/ actress. Who, while happy with Peter eventually watched by as he got more and more consumed with his life of Spider-Man, to the point where she barely recognizes him anymore... and then that is where SM3 picks up; where they are still happy, but that Peter just has touches of pride/ arrogance and that MJ's life is sliding down.
It doesn't excuse the things she did and the way she was written. I will say coming from the words of Avi Arad himself the series often seemed to be 'Beat Peter Parker up.' You see this in full significance in SM2, where his life just goes from bad to worse and worse again, until he finally gets MJ. I agree MJ was often used as a plot device as she was 'the girl' he had to win. I also think Mary Jane perhaps had some kind of misguided idea that she was so much more fantastically beautiful than Peter and that he was very lucky to have her for that reason. The problem with that is that Kirsten was neither anymore attractive than Tobey, nor did the team try and make her look more appealing or alluring, to at least be able to see visually why all these guys would be going gaga for her. If they'd hired Elisha Cuthburt who I know auditioned for the part, this might have made sense. Because lets face it, her character wasn't funny, charming, kind, considerate, smart, and by the looks of SM3 a particularly good performer either, all she had going for her really is her looks, which she didn't have.
But truthfully, that should not really matter, because regardless of who was in the role, she still would have seemed *****y and selfish. I guess you can blame 1. The writers/ producers 2. Kirsten for insisting of having Mary Jane look plain and 3. For Sam Raimi for needing it always to be 'Make Peter's life as hard as possible.'
TOM HOLLAND FOR SPIDER-MAN 2017!