How much do we really want Customization and Coordination?

[Shurrikhan]

I've been thinking a lot about what could be done to try to give a greater sense of identity within one's own character and between it and others, especially within combat, but I come constantly across an obvious question, "Is what I'm looking an outlier among the wants of the larger community? Are there elements I want that most others will not, or elements that a majority of player desire that I have not encompassed?"

I'm presently working on a poll to try to better quantify and visualize these things, but I could use your help in adding categories, lest every section end in "something else". If you'd be so kind, I have a few questions for you:

1. What are the elements of combat you most enjoy in this game? Moreover, what makes a particular run of a fight memorable?
(For that matter, what do you most dislike, and is there ever a factor necessary atop the rest to make a particular combat experience go from average to excellent?)

2. Assuming it were possible to balance jobs and any customization therein such that no person's time spent leveling and gearing a given job should ever be wasted going into a given piece of content, and each build usable for a majority of content, to what degree would you be interested in seeing customization for jobs and classes?
(How could increased complexity or esoteric knowledge be minimized while bringing forth maximal identity and attachment to one's character? How might this affect the burden of knowledge as to what other jobs are bringing to the fight?)

3. To what degree would you like for your in-combat decisions to be made with reference to your allies' actions? How much dependence and synergy would you like to see, and how might you imagine that would look, or what (kinds of) mechanics would bring that into play?
(If there are both negative and positive impressions that such a system may give, e.g. "dependence" vs. "synergy", how might one make the positive more present or ostensible than the negative?)