mkay, first and foremost, if you're not getting a response within a day of posting the question, chances are either your question is too difficult, or not stated clearly enough. posting three times in succession in almost as many days will do nothing but get you the wrong kind of attention, i.e. from a moderator.
to the questions -
yes it's possible to script a winch/towcable, in fact there are several such resources on this site if you care to search for them. however, it is not an easy thing to do, especially when incorporating it into a standalone addon.
yes, you can make ai soldiers fire upon a chopper, but it's pretty difficult - again there are numerous threads on this site dealing with the problem.
as for the rules and regulations concerning designing and releasing your addon to the world at large, all the information you require will be in the EULA (end user licence agreement) which you will have had to accept before installing the game. if your question regards copyright implications concerning the original game, google 'copyright' and 'fair use'.
while they may be short your questions are not 'simple'. my first suggestion would be for you to use the very effective
search function and have a look at the 5+ years worth of posts to see if that yields solutions. you may be surprised at how much it turns up.
main thing is not to get impatient if you don't get a response to your question - there's a wealth of information at your fingertips, and if you do some digging first, chances are that your question will develop into one that will get a response.