"Step 8: Click Damagae in the Side Menu. Change the Value in the box. Changing it to anything too high will crash your game."
It won't crash the game, FE just won't let it happen.
Also, I doubt anyone would set the damage too high, because it is a float. The limit is 2305843009213693952 (yes, that's more than two [fictional number ending with 'illion']).
Also, the link to the tutorial up for download gives a 404. Might I suggest changing the address it links to, perhaps to
this?