1) The first one
2) Because if a trance style track has a beat, I think it should be faster than the instrumental version. Some of the Deep & Chilled euphoria CD's demonstrate this well, slowed down remixes of more uplifting trance tracks - this is personal preference of course.
3) Not on it's own, but if it was part of a compilation / mix CD by a talented DJ, yes.
4) I don't fully understand what you're asking to be honest hehe PS, it's a long shot, but do you have the Wav files for each layer? Would quite like to do a remix