[Strange Problem with Headphones' Stereo]

From what you've described, it sounds like the "mid" is getting canceled out and the "side" remains. That would be why you're hearing more reverb too. Are you applying anything that would change the stereo imaging to your channels? example: Are you turning the 'stereoize' knob in FL Studio (don't use this one anyway). Maybe you could check if something is being canceled from your output by throwing a vectorscope (Wave Candy) on the 'Selected' channel?

[Stereoize - Gravity Beatdrop (Megaman X3 Gravity Beetle)]

SON OF A no wait you're right, I hadn't looked at this track for a minute, good to get a sanity check before submitting. I certainly had too much gain on the multiband for 2khz and above, that and the EQ on the lead create some nasty sibilance. It certainly does not clip because of the maximizer, but that is no substitute for a good mix. So that was useful.

[What do you use for organic/symphonic sounds?]

Use volume automation on swells, play with the attack/release of your string sounds, randomize all your velocities when layering sounds, adjust the velocity sensitivity of your patches for starters. Gear doesn't really matter, I could get a better sound out of Edirol than someone that doesn't know what they're doing with East/West.

[Stereoize - Gravity Beatdrop (Megaman X3 Gravity Beetle)]

https://soundcloud.com/stereoize/gravitybeatdrop

Been producing for a while, but first submission to OCRemix. I don't really have any worries about the quality of this one at this point, this is more of a showcase. If you're a fan of bLiNd, you'll (hopefully) be a fan of me too. 2:00 is where the real fun begins. Feel free to check out my other remixes, you can hear a lot of stuff on my soundcloud page before they wind up here.