the apu will be just fine, the a10 is ~$140 USD
http://www.amazon.com/AMD-A10-Serie...UTF8&qid=1431456803&sr=8-1&keywords=a10+7850k
with price cuts to ~$120 coming soon.
wow raid video
https://www.youtube.com/watch?v=B5VIHwPlRgo
if you decide on the apu just try to fet 1866 or better ddr3 memory.
GW2 will eat an AMD CPU alive, it absolutely loves ST CPU performance.
I haven't played for a year but 50 - 70 person W vs. W vs. W fights for fighting a world boss with ~50-100 players brought the game down to ~10-20 fps on a 3630qm on the lowest settings due to CPU limitations. I could use the HD 4000 instead of the dgpu because the CPU limited the fps so bad and not notice a difference.
Sometimes someone would shout out "FPS?" and the chat would say something like this.
-8
-10
-5
-12
-9
-15
-13
Then there would always be that one guy with a 4.5 ghz intel CPU and 25 fps. But basically no CPU on the market could reach 30 fps minimums.
This is from October 2013 and shows the kind of CPU demands crowded areas have.
I have some of the more demanding settings turned up (shadows, shaders, character model limit) but basically the game is completely CPU limited on a 3630qm (3.2 ghz IVB quad) and a 660m OC (desktop 650) to 25 fps.
720p and 1080p screen shots taken a minute apart.
Go into an abandoned area and you can get 150 fps easy but once there are people fps tanks like a rock. The screenshot above was taken during an event so the load is a little higher (area is generally around 30 fps). But you will experience said conditions a lot if you play a lot of the biweekly events.
IMO I believe GW2 uses three main threads and 2 light threads.