I invite you to check the tutorial about licenses
But basicly (I suppose you bought the standard license) you're already running with a license that allows you to use construct2 and make a little profit out of it until you reached the amount of 5000$ (5000$ of profit made out of the game mades with C2).
If (when) you make more than 5000$ of profit, then you'll have to switch to a business license.
Also, it is my personal belief, but I don't see C2 anywhere near becoming a dead project. I believe it might even definetely become one of the (if not THE) major players in HTML5 game making.