The smell will be there, regardless of the brand, when going catless. If you're moving, it's barely noticeable. If you're idling in traffic, you'll definitely smell it.
I get the same feedback/sound, almost like the throw out bearing engaging. Whatever it is, it's coming from the engine bay, and it's something that bugs me when the music is off :)
I've got the Skunk2's on my Si, and I can't complain. They have a better overall drop (in terms of wheel gap) than the Eibach's (IMO), so I went with those, and haven't regretted the decision.
Will do, where should I send it? And yes, USB is disconnected. I do, however, need the USB to ensure it connects, otherwise the light is always red when I plug it into the OBD port.