There are plenty of opportunities for you to leave your mark on the shape of our world. Just remember a couple of things:
I may alter your suggestions before I accept them, if I accept them at all. If I don't agree to something, it's no reflection on the quality of your idea but rather that it doesn't work with some aspect of our system.
Ripping your ideas wholesale for our original fiction wouldn't be nice, so we won't. In the context of this forum only: Any suggestions I do accept are open to everyone. We need not ask your permission (though, as always, creativity in using someone else's idea is encouraged).
Nor are we obligated to stop using your ideas if you leave us. (Sniff.) If you ask nicely, we may agree. Of course, we may not, especially if they've become important, character-wise or plotwise, for people who are not you.
Also if you ignore this disclaimer and then get upset when you see someone else using something you thought up for this forum, we will point and laugh.