do you think we can include in this competitions to specific composers, as in, "I challenge you to a competition" and the two would write a piece and someone would judge it and one will be the winner while the other cries in shame? like a fight but without the fight. I dunno, it just seems like a fun idea
Don't worry so much about whether you've heard the melody you're using before. If you spend time on developing it and work with the melody, there's a good chance you'll end up with something of your own anyway. Going through life trying to only come up with original melodies sounds like a dry experience. If you like a melody write something for it, just remember to develop it and not just let it be as it is.