1) Someone spouting fantasies of genocide should be responded to harshly. Had I been anyone OTHER THAN a Muslim no one would have construed it that way. Blame prejudice, not my response.
Given the prejudice that exists, your phrasing was reckless. You're in a public war of words with someone-- how you phrase your response is everything. What I find amazing is not that you made an angry, off-the-cuff response to thunderf00t but your total unwillingness to accept you could have phrased it in a better, more responsible manner that would have mitigated any prejudiced interest from law enforcement.
2) Its not as easy as you think. Internet speech laws are more lax in the states.
I live in the US, I am well aware that due to the First Amendment, it is difficult to sue for libel, slander, or defamation of character. But you could get an attorney to send a "cease and desist" letter for under 200 bucks assuming you don't know or find someone who will do it pro-bono or at a minimal cost. Even if you don't know anyone you could probably get it done for 50 bucks or so if you draft it yourself. And here's what happens typically when someone gets a cease-and-desist letter from an attorney-- they get their own attorney who then contacts yours. Since lawyers are risk averse and make more money negotiating settlement than in actual litigation, they will advise their client to work out a settlement agreement, even if it's not a winnable case in court-- in the end you get a settlement both lawyers are happy with cause they made money off it, and that both potential litigants can live with cause their drama is done.
Prior to consulting an attorney, however, I spent several months trying to have a normal conversation with Tf00t, which he kept declining because I "deserved it" because "I believe in a stupid religion".
Several months? As soon as he said anything like that in the first place, if you were behaving civilly and politely in the first place (as you seem to imply) in your conversations with him, then that should have indicated he was unwilling to be cooperative and you should have unilaterally terminated the conversation with him and sought third-party representation for any and all communications with him. Several months of communicating with an uncooperative person to resolve a personal issue is either unnecessary internet drama or stupidity but it is NOT effective conflict resolution.
3) I did and then I served his ass to him later.
Right, you rubbed in the pay-back you got on him and then complained when he made those communications public. Reckless.
4) I wasnt being reckless. People lied about me. End of.
See above. It was reckless because you sought payback then snidely communicated that payback to him, then complained about him publicly complaining about it, when, as you were already in a public war of words, it should have been anticipated that he would publicly spin your actions and communications against you. Reckless or stupid. Revenge is a dish best served cold-- you don't seek vengeance then send someone communications taking credit for it, especially when your spat is already public and that person can reasonably be expected to use any of your communications against you. How old are you? If you're under 26, I'll give you a pass, if you're over 34 I give you a facepalm, in between I'll roll my eyes and say I hope one would learn from this and not repeat it at your age.
Anyhow, thank you for continuing to respond to me here calmly and rationally.