So I have been trying a few things and yesterday I had a black screen free day!!!!
I'll list the details of what I did in the hope that it helps somebody in the Future.
It seems to me that my GPU fans were not switching on/ running fast enough to cool the card correctly. I only noticed once I removed the card after a crash and found that it was very hot. After putting the card back in and lying on the floor and physically watching the fans I found that wattman was reporting they were running when in fact they were not.
After uninstalling all amd software, I used amd's clean uninstall utility to remove any trace of their software and reinstalled the latest drivers. Fans still not running correctly, why I don't know? What seemed to fix my issues was using wattman for force the minimum fan speed to 50%. I managed to stream for hours and even get in a few rounds of PUBG.
This is obviously not the greatest fix but at least a workaround that means I don't have to bin my Graphics Card.
Hope this helps somebody.
Ok so now i have no black screen while streaming but while playing Xcom2 today had a black screen/sound loop crash every 30 odd minutes. Back to square one, starting to hate AMD.
Anyway, the search for support continues