Winstun
It may be worth noting the following:
Most people on this forum realise that you are a 'character' and that your posts are meant to be taken in jest. This, however, does not absolve you of responsibility for the content of those posts.
Having a bit of fun (e.g. telling people you are a multi-ATPL, paralegal, amateur surgeon who speaks eight languages and can maim in a multitude of ways) is all OK and is taken in the spirit in which it is intended, i.e. not to be taken too seriously.
On the other hand, some of your 'banter' has probably gone a little to far. Taken at face value, you have threatened the commision of a crime (wilful murder). While most people here will realise from your previous posts that you do not intend to be taken seriously, you should probably be careful how far you take the 'Winstun' character.
Even though we are all aware that you are not seriously going to 'assasinate' the next drunk on an aircraft, the mere fact that you have threatened to do so may be seen as a crime in itself. In this day and age (and the ease with which ISPs can be traced), it is unwise to publish criminal intent. Proving that you were 'only joking' becomes very embarrassing, both to you and your parents.
You should probably tell your parents what you have done and make sure that it does not happen again.