So I had some time to investigate the hub issues with the pi / linux. The ANKER 7 port USB 3 hub I'm using has the VIA chipset, which apparently is not fully USB complaint and has some major firmware issues, and is the reason why it does not work with the pi (I'm assuming the hubs you guys are having issues with probably have the same chipset).
Main issue cause these is outline below (one of the pi developers) :
"USB1.1 devices plugged into a 3.0 hub on the Pi are not something a gpu firmware or driver change will fix."
Since then, I've confirmed that it is indeed a bug with the VIA chipset (by substituting a different USB3.0 hub chip).
The workaround is to purchase a USB3.0 hub that integrates silicon from a different chip vendor, or get VIA to admit their spec noncompliance (no prizes for guessing which will be easier). SMSC/Microchip based USB3.0 hub IP works with the OTG port on the Pi, I have yet to see any other vendor USB3.0 hub silicon in interoperability tests with the Pi.
The full read of the discussion is here, its quite interesting nerdy stuff https://github.com/raspberrypi/firmware/issues/64
There is a proposed fix by adding the line
to /boot/cmdline.txt file of the pi's SD card. I have tried this and it indeed does recognize the sticks and starts hashing, but the USB bus quickly crashes afterwards and reboots the pi.
This fix *might" work for some hubs / other linux systems but I wouldn't hold my breath. This just shows you how cheap these hub manufactures are and they cut lots of corners. Of course these issues don't show up until they are stressed out by devices like high powered USB miners.
Its interesting though that this particular hub works fine with 5+ miners under Mac or Windows, so seems to be an issue isolated with the VIA chipset and Linux USB drivers.