I define cheating in probably two ways.
a} If you don't have to do any work setting something up, but just type in a command to get something.
b} If as a result of a}, what you're getting is not due to any in-game mechanics.
Equivalent Exchange does require work in setting up infrastructure, and it also apparently has a set of internal mechanics which it follows. So logically to me it isn't cheating; although in the case of item duping, it certainly can feel like it. If the mod allows a chest full of lava cells to be duped, then I would hope there is some serious work that you actually have to do to get that result, and that there is a coherent reason for why it works, in game terms.
If you have a X-Ray-mod installed, then it's not cheating???
I just wanted to apply your Logic to some Cheats.
EE not even requires large amounts of work to be considered as cheating, because the Transmutationtable is the only cheat there. If you want to have an Godsuit then you have to work hard for it, i know. But it's the Transmutationtable, what's considered cheating.