You don't need to know anything about JCS. All you need to have is a sense of what makes a level good or bad. And in most cases, that simply boils down to one question: "Is this fun or not?" It also helps to be somewhat good at single player levels (the difficulty is quite high) but easy mode should balance things, and really I recommend easy mode for most players.

In any case, once I think it's ready to start testing I'll private message the people who have offered to test.