Well one issue you have with your build is the OS isn't on a SSD. You MinMax out all the other components then settled for a 7200RPM for everything. Honestly, any good gamer's build has a SSD for the OS and then games on the TB drive, to get 'Windows' out of the way, as you want best performance for streaming.
Secondly to that, if your planning to stream you need to consider more than the rig, there is alot of issues with gaming and streaming from the same rig, especially if your expectations are (for example) 4K Ultra Game settings and trying to 1080P Stream all at 60FPS on both sides or better - this rig wouldn't cut it. Further, unless you do some serious QoS on your Router/Modem and tell everyone else NOT to be on the 'net' (even...