Seems like a solid build and performance is basically what you'd expect. I don't really see anything that can be changed for a big performance boost unless you spend quite a bit more money on a an i7-8700k + GTX 1080TI.
That said however, there are a few things I'd personally change if I made that build for myself.
- Your motherboard and memory doesn't play particularly well together (as you've discovered with the crashing). The G.Skill Ripjaws with part code F4-3200C16D-16GVGB uses Samsung E-die (Ryzen prefers B-die) chips. You can see a list
HERE. 2933Mhz is about the limit of what you can get from Samsung E-die memory.
Your motherboard, from what I've read, also seems to not like high-speed memory all that much.
I would replace these 2 components with something like a Gigabyte X370 Gaming K5 + G.Skill Flare X 3200 MHz CL14 memory. That mobo also has a clock generator allowing you to fine tune the OC on your CPU and RAM even more.
High-speed + low latency memory (the latency in particular) gives quite a noticeable boost to Ryzen CPU's, especially the minimum FPS in games which is ultimately what matters to get rid of that stutterin feeling. Going from 2933mhz cl16 (presumably?) to 3200mhz (or above) cl14 would definitely be noticeable. See this video for comparisons:
Another thing I'd change is the SSD. 128GB really is just too little, and trust me, you won't wanna have games on a normal HDD for very long when you get used to the speed of an SSD. The Adata SU800 is also a very budget SSD. I guess it's "ok" in the 128gb category because honestly all small SSD's are quite bad, but I'd definitely look at something like a 500GB Samsung 850 Evo or Crucial MX300 instead.