So if I'm not having ANY issues with a 64 ohm headphones (ATH-M50x), then I should have no issues with a 100 ohm HMD 26-II, correct? If thats the case, I should just get the 100 ohm version so I dont need more amps to drive my headsets, right?

Tried all that... didn't make a difference.

Yes, the sound goes away when I mute the mid... However, the mic is WIRED, its not wireless... so there is no RF receiver.