However you want to slice it, "******" was rapidly adopted as a derogatory term for homosexuals. Barring childhood innocence, people know this. And as with most offensive words and phrases, you certainly have a right to say it, and people have a right to judge your character poorly because of what you say. The fact remains that if you are willing to risk letting people feel bullied and marginalized, even if your intent is not to bully or marginalize, you still took a conscious, completely optional action that you knew could hurt people simply because you like the word. That is still a bully.
If you use of a word that can hurt someone you either A) Valued a word you like that has plenty of other, less ambiguous substitutions more then you value the well-being of fellow human beings (Translation: you're an asshole) B) You genuinely believes that the people listening are fine with the use of the word based on your personal experience with them (In which case, if they are offended, you don't have to fall on your sword, but you do owe a short, sincere apology) or C), You are a professional comedian, writer, or entertainer where the use of a offensive word serves a purpose, and the audience should expect such digressions from normal decency standards. Louis CK can say, "******" in his show because people know that he is going to say dirty, inappropriate things. If he just started spouting his act on a subway to whoever is around, that would be in bad taste. Chances are pretty good that if this conversation actually comes up in the real world, then scenario A is probably in effect.
Also, there is a serious problem with the idea of "It's used as a general insult, not a slur" This is not an excuse. The word came to be a term for gay people, used by people being cruel. But nonetheless, it still is a word that is supposed to mean a homosexual person. It is insulting to equate a word that means something bad with a gay person. If a person named Adam is being mocked, and he is called, "A total Todd", because Todd is a kid no one likes, then that insult is offensive to Adam sure, but its MORE offensive to Todd. Calling a person a "******" because they are a failure implies that Homosexual=failure. If you heard 2 gay people talking about Hitler, and they refer to him as, "A total Breeder", you would probably be offended. And rightly so! The the use of a word that means a sexuality as a word that means something bad implies that that that sexuality is inheritly bad, and the words are interchangeable.
Basically, if you use the word, "******", you own your slur. If someone is hurt, that's your fault. If everyone laughs because they understand the context, that's your boon. If you use the word for a legitimate reason and it offends people, you have to balance the true value of the message with the true value of disregarding and harming a fellow humans well-being. And if people think your a dick, that's no ones fault but your own, because you brought it on yourself. "Idiot" is one extra letter. Unless your afraid of running out of sound, theres no reason you can't use that instead.