This is me trying to get into cEDH, and more and more cards being kinda pushed into it. There are so many interactions, so many triggers, my mind just shuts off, and I feel extremely bad losing one game after another because I was just overloaded with information. To point of seriously considering quitting MTG altogether and picking up something simpler, like plastic models.
GW2 is extremely CPU heavy, so you want to get the best CPU you can, as you said especially taking into consideration single core performance. GPU is of less concern so you should be fine with what you have I think. I run it on Ryzen 5 1600, and RX580 8GB. It runs alright, but you can really hear it. Biggest effect to me were CPU and SSD upgrades