You might want to look at the set up Resolve (
this article discusses some settings and hardware issues, with some testing
here).
Some people have reported many bugs Resolve had with various hardware. The latest Resolve updates should have sorted that out (you downloaded the latest version?).
The iGPU should be inactivated, as CaseySJ indicated, as an active iGPU can make Resolve less stable.
The 475% CPU usage you report is a little bothersome. It should be more like 80 to 95% during max use. I may have missed it, but are you over-clocking? If so, perhaps lower the settings. (If at 5 GHz, maybe try 4.3 or 4.5 GHz.) And, have you set the AVX in BIOS to something like 3, rather than leaving at Auto? That might help.
In looking at the DaVinci spec requirements (
here), you should be fine. In the preferences section, you can specify how much RAM is used by Revolve. I've also heard that selecting DNxHR SQ in the optimized media preferences section may help reduce CPU overhead (but at a cost rendering time and storage space).
Are you over-clocking the RAM? I've seen stability improvements by decreasing the DDR4 speed, in 200MHz steps, from the maximum rated speed. The overall loss in computer speed by the reduction is trivial vs the potential for improved stability.
Another source for Resolve crashes in inadequate file permission. Maybe give Resolve full access permission in System Preferences/Security & Privacy/Privacy/Accessibility section. And also check the permissions of the folder where files are being read and written to: highlight folder and right click for "Get Info". Then, at bottom of this window, allow "Read & Write" for all users.