Regarding the bulleted points, at present I am inclined to choose B over A, but given the disparity between the packages (and the fact that A is also an excellent place to pursue some of my AOIs and philosophy more generally), I haven't sufficiently reflected on this inclination to say definitively that I will or want to choose B. Part of the issue is that A and B have slightly different (but related) strengths, and I haven't personally decided which path I want to take (my application kind of straddles these two AOIs). A further complication is that I haven't visited A yet, but I feel that if I were to negotiate with B, I should do that sooner rather than later to give them a chance to discuss internally.
If B were to increase its package even by $1k I think it would be sufficient to take B over A. Perhaps it sounds silly but there is some psychological comfort in being shown that I am really wanted by a department. I don't mean to suggest that this whole process is some sort of game; at heart I am essentially concerned with my living conditions, as it will be quite expensive to live and attend B (and likewise for A, but A's package seems to acknowledge this expense more frankly than B).
So, I think I would want to say (to B ) that I am having difficulty choosing between A and B, that I am inclined towards B, but that the decision would be much easier for me if B were able to offer any sort of extra remuneration. What do you think of something along those lines?