On the issue of Aftermarket Modifications, parts replacement under warrantee:

First off, I am a long time modder so that is where my mindset is...

That said... here comes the big "However"...
If you do mods to your car, and those parts that you are replacing standard OEM parts with somehow are involved, directly or indirectly with a warranty replacement...

You should not expect your dealer to replace modded parts if they are somehow involved in a warranty cure.

In this particular instance, I would think that common logic states, that XFiring should not expect his dealer to replace Rotex brake pads.

That said, because Rotex brake pads are your mod, and IF the dealer can show and PROVE that the Rotex pads are a "cause" of the problem, then you are in a hard place. The rotor is probably not covered under warranty but could be, depending on the stance of the dealer. I would assume you have three other rotors that are in good shape. The caliper is the opportunity for warranty work IMHO. The brake fluid is not covered under warranty in this instance IMHO.

I would go to ROTEX and ask them if they can make good on the pad replacement if needed (ie: at cost).

That's my two cents... for what its worth...