Hi, Memor-X, long time no see. xD We're hanging out in discord most of the time now, FYI.
As for you questions, unfortunately you can't sell your game, even if you alter the script.
That being said, I usually don't mind people using my scripts, but I want them to explicitly ask first. That way I know if somebody stole my script in a commercial game or not. I'm pretty sure most people here at CP would give you permission for their scripts as well.