I don't know why people have a buffet style method. I suspect they choose those aspects that alread fit their life.
From an historical perspective, you ahve to look at what Leviticus was supposed to be. It , for the most part, was rituals and customs that dealt with the priesthood, and the temple.
For example, in Levitucus 20, when discussing the sexual realtionship with a slave if she is 'bethrothed' to another man, Although technically the betrothal has not happened (since she still is a slave), it is saying that the offense against God still has to be dealth with. The "ashram" offering of guilt has to be satisified (see levitucus 5:14-26). So, in the context of the time, it is basically saying that devotion to god has to meet the spirit, rather than just the legalities.
THen, look at the mixed fabric prohibition. The Priestly fabrics of the time were made of linen and wool. By prohibiting people to use the same kind of fabrics as the priests, it was making a seperation between the sacred and the mundane.
Now, when it comes to 'a man also lie with a woman'. .. you have to also some other parts of the bible. The 'homosexual' act for the ancients was basically an act of force associated with humiliation, revenge or subjecation (see The Jewish Study Bible, page 251). It is this act of humilation via sex that they are talking about (at least one interpretation, also see Judg 19.22). They were not talking about a loving same-gender relationship, because they didn't acknowledge that existed at all. Now, the Orthodox Jews also have certain sexual
restrictions, but that is more about the 'waste of seed'.. (silly in my opinion, but hey, different strokes and all).
I don't think that the laws of the Leviticus are even UNDERSTOOD for what they were by most. The cultural context has been lost, or made irrelevent. The translation of 'abomination' is actually better translated as 'ritualistically unclean'. And, it specifically dealt
with the Jewish relationship to the temple, and rules that the priests have to follow also.