re: Danger of sawdust combustion?

I agree with Thorrean.
Disclaimer I am NOT an expert (of anything), but I am an industrial electrician with some experience with grounding massive dust collection systems.
When I built my shop I took some time to research dust explosions more carefully.
It is a risk albeit small, in small shops. the risk is actually higher when you are sweeping. It is all about the fuel/air ratio, which is usually low in a small shop. If you keep your shop well swept and dont let the dust pile up you’ll be fine. Grounding is ALWAYS a good idea but I strongly suggest driving a separate ground rod and grounding everything to that. Dont rely on the ground from your panel as that (in rare cases) can actually introduce electrical energy to the wire. (That is actually the purpose of the grounded conductor).
research dust explosions, there are a lot of good resources online (youtube)
Knowledge is power.