As VanDattum said "the more realistic the scene looks (like that it could happen in real life), the more arousing it is". But for me this means that the best plot is girlfriend/boyfriend when both of them are enjoying (specially her). Enjoy for him does not mean physical pleasure, but emotional link with the girl, who can be (who I prefer to be) really cruel. So I also prefer to see him trying to resist, but unable to stop her. willing to be in a helpless position, at least until the torture starts, and it is too late. And this is why bondage is so important.

naked vs clothed vs scantily clad [both the ballbuster and the guy]
both are ok. I definitely not prefer the whore dress type, with strange colors and clothes nobody would wear in real life.

do like to see him 'enjoy' it, or do you like it when he 'resists'
As I already said, they are not incompatible

do you like a silent ballbust, or do you like it where she teases, mocks humiliates....or [deliciously, for me] where she shows mock gentle concern and asks if his balls are hurting.
I prefer to hear her talking. But I hate when they shout, or seem angry with no reason.

do you like all/any age of ballbuster/ ballbustee....or do you have a preference eg: i like it where a mature women in a position of power, ballbusts a much younger, preferably much shorter guy.
do you prefer a petite girl to bust a beefy big guy, or like a tall amazon to bust a weedy guy.
I agree with VanDattum. Midle age, and expirienced is the best. Amateurs learning can also be exciting, but not too young, please. All sizes are good.

do you prefer her to look haughty and contemptuous as she does the busting, or do you like her to laugh and giggle.
Laugh and giggle are marvellous, the most precious attitude in a dom. But I admit that it is very difficult to play a natural laugh. So sometimes it is better to just do not pretend anything and concentrate just in the action.

do you prefer them to seem like total strangers, or do you like to think of them as girlfriend and boyfriend. As I said I prefer the most realistic, so the latter. That also applies to the scenario. Why a simple room so hard to see? the dungeons are ugly and cold.

do you prefer to see a single devastating couple of kicks or knees....or do you like to see multiple kicks for minutes at a time.
Multiples, never ending ones. I am no fun of knees, least kicks. I prefer hand slapping, a lot of manual stimulation of his balls.

do you prefer to see a guy busted by just one, or by more than one girl.
One is best, but more is ok.

do you see yourself as a spectator, or do you imagine yourself being busted in place of the guy in the clip?
Both