I have a much simpler and less discriminatory definition.
To say that "X" has a cause simply means that "X" has atleast 1 requisite in order to exist.
Sorry, what does it mean to be a 'requisite to exist'? Doesn't it ultimately mean that there is some law of physics that goes from one to the other?
To say that a man is the cause of the watch simply means that the watch requires (or required) the existance of that man in order to exist.
Nope. it means that some human, working thruugh the laws of physics, was able to make a watch.
The curvature in the couch requires the ball, therefore the ball is a cause of the curvature. Without the curvature the ball would still exist, but without the ball the curvature wouldn't exist. This is why the ball is the cause and the curvature the effect.
The curvature wouldn't exist except that the law of gravity produces a force and the laws of distortion produce the curvature.
This is what is meant by "cause" in the KCA
Well, then it uses an incoherent concept of cause.
So given this definition, do you still reject the conclusion of the KCA? (the universe has a cause)
Do you still reject the possibility of simultaneous cause and effect?
Yes, I do. To both. I think the definition is incoherent. The notion of 'requisite' is both useless (it ultimately means through some mechanism) and irrelevant (logical necessity isn't a form of causation).