I think you did a very good job presenting what you have presented in the above post. And, while these days I normally avoid conversations such as this like the plague (or the swine flu), I feel compelled to mention that just as you have presented what you have from the Holy Writ . . . probably as you know, others can take the same Holy Writ and make an equally good presentation for predestination Calvinism/Augustinianism whatever you want to call it.
This is why I don't want to participate in these discussions very much anymore about which "side" is correct. I have attended one Calvinistic bible college, one Calvinistic seminary, and two other seminaries which have leanings towards Arminianism. In my early years I would go round and round with this (always arguing against Calvinism). But, over the years (different faces and places), in the end, 'they' would use 'their' scriptures and the fathers and logic/reason to argue 'their' position . . . 'I/we' would do the same with 'ours' and nothing would be changed. In the end, there is nothing more than a trading of well honed responses. After the usual scriptures were quoted, then the next step is the explaining of how the other side has not used a proper hermeneutic in their understanding of what was written, and in turn each side is making a poor application. If some up and comers who were not familiar with the issues were present sometimes their could be some influencing of minds going on there; but, overall it was a big waste of time.
Somewhat as I have suggested in the theopoiesis/theosis thread, I wonder if the answer is found in the knowledge that God has predestined some from the womb to be His, but in other cases it is just as you have presented it to be?
I wonder if it is possible that there is not one right answer here. While John Cassian writes of a middle way (which one side views as being semi-augustinian and the other side views as being semi-[or full-blown] pelagian), I wonder if it is possible that there can be no dogmatic stance on this because there are varying degrees of these aspects at play in the lives of individual people on their respective paths? I wonder if even here we see that one size does not fit all?