as far as the 6/8 i just like that time signature lol
I do like 6/8, especially writing in it. A big reason is that it's duple meter with a triplet feel, that's one of the primary characteristics of it. I can't hear the pieces here because they're unavailable for some reason so I'm just trusting what anacrusis said.
Take the first variation of Bach's Goldberg Variations (attached), which is in 3/4, but can easily have six counted instead, so could be 6/8 perhaps, or could be in 12/16 if that was the kind of thing people did. It seems fairly arbitrary to me. I know the idea is that in 6/8, you'd have a secondary emphasis on beat 4, but who says you can't have two secondary emphases on beats 3 and 5?
I also have a vague memory of learning that the choice of note value in the time signature is to do with a range of tempo traditionally allocated to the notes, but that's maybe a separate issue.
As far as I know, the difference between 3/4 and 6/8 is usually the location of the downbeats. 3/4 is usually ONE two three. 6/8 is ONE two three FOUR five six. So the rhythm sort of goes in threes in 3/4, but twos in 6/8.