EpicSOB

it was the ram, the ram must have been off my 1/100th of a hair off, because when i tested the ram 1 stick at a time this morning all the issues went away. when in doubt reseat your ram apparently. 

Yes, a 500W PSU provides enough wattage, I have an R7 1700 and a RX580 8GB powered by a 450W PSU, max draw of my system is around 340W so you will be fine. That said I recommend a PSU upgrade to a higher quality unit in the near future. PSU voltage ripple can permanently damage components for good, better off spending a bit now versus replacing expensive components later. 
 
Refer to the PSU tier list linked below. I recommend tier C or higher, Corsair CX unit is usually found on the cheap end and is a good PSU.
 

The stats are from here
https://folding.extremeoverclocking.com/search.php
 
search for your username you created for - it might not show until you start folding and do your first WU
for e.g mine is https://folding.extremeoverclocking.com/user_summary.php?s=&u=830593
 
Yes you can use multiple PCs - make sure you use the same username and passkey