I don't know a single Christian that believes you need the Bible to be a good person. One of the major messages of the Bible is that man's goodness is never enough.
#1 - Exodus 21:7, and the word used is servant, not slave. #2 - Exodus 31:15 #3 - Deuteronomy 22:9, and it says nothing about stoning. #4 - That would be Deuteronomy 14:8. One thing you left out, with every single one of those examples, in a verse before or at the beginning of the chapter, you will find that these were the rules for the Jews. Christ's death on the cross fulfilled the old covenant and brought in the new. Because of that, the old laws are no longer necessary. In the early church era, the apostle Paul preached against the Judiaising of the church, as some Jews were saying that new Christians had to also follow Mosaic law. (Galatians) So no, we don't follow the old testament laws, not because we choose to ignore them, but because they are now unnecessary. The argument you use is flawed, and unfortunately, quite commonly used.
Who cares? I do for one. First off, some of the major pillars this nation was founded on are freedom of belief, freedom of speech, and freedom of assembly. When gay groups decide to go on personal vendettas and bring law suites against bakers, photographers, caterers, other wedding vendors, and pizzerias (who on earth goes to a pizzeria for wedding catering anyways?) because they dislike they idea of going against their personal convictions, I have a problem with that. Pulling such shenanigans doesn't earn anyone's cause any respect in my book, quite the opposite actually. I'm not a jerk, I don't walk around and offend people on purpose, but If my beliefs offend someone, I really don't care. My first amendment rights are more important than anyone's eggshell feelings.