This is pretty interesting...you have a lot of extra stuff in there compared to how I use them. All I can do is suggest a few things that we have done with great results.
First off, it truly makes a big difference how good in quality the mixer is that is sending you an aux. I have had my PSM200s for over 8 years now. Until a couple of shows ago, we usually send out our auxsends from some form of Berhinger mixer. If you keep an eye on the limiter of the PSM, it would hit yellow/red and clip pretty quickly. Our PSM volumes were pretty low. Just recently, we got a soundcraft board for the auxsends, and a split snake, and keep that mixer onstage. Saying that there is a night/day difference in what comes through that mix is an understatement. You can just get such a hotter, cleaner signal before the PSMs start clipping. It's so much less fatiguing. With all of the equipment that you are using, there is a good chance that you are not getting the best signal that you could into that PSM. It's hard to say because every mixer is different. You could try just sending a DI and mic into the house snake and let the soundman adjust your mix for a show or two, and keep the PSM with him, or let him send the aux back up to the stage for you. Bypass all that other stuff you are using and see if it cleans up the signal and your vocal mic. Hopefully it does. What you hear in your ear should be louder than your "head vibrating" volume.
Since you aren't using your PSM when you are wired (but maybe you are still using the beltpack), it kinda points to the aux send not being what it should be from the FOH or your little mixer you mentioned.
Also, the spacial effect will be remedied some if you are getting a bit of mix from the other mics on the stage, or just a didicated one out front. We never use additional mics out in front of the speakers though. We have some 16 mics on stage already!
Just try some stuff out and let us know.
Wes
