Well, first of all, don't cheat. Now, what particular anti-xray plugin are you talking about? There's different approaches and it's impossible to help you unless you're more specific. Also, to know if there is a mod better than the one you're using, one would need to know what mod it is that you're using. In terms of editing an existing mod, sure you can, just become a java guru, run the jar through a decompiler, figure out how to works, change it, and recompile it (so that answer is no).
all of them are turned to air blocks than being invisible and i can't find a single ore unless its exposed to a cave like near lava or an opening and some made an antixray that made coals to gold, iron or tnt but when you mine toward it turns to coal.