If it's fusarium not much you can do about it but pray. The seedling will either live or it won't. You'll know in a few days. If it doesn't fall over and die then you're fine. If they make it to the second set of leaves they usually live.
Have plenty of experience with spider mites, but heard many varieties. Do you think this is them, they look too clear from my experience.
Second picture is other bugs. the tiny rice shaped things are everywhere, and the big thing in crevace. Had stink bugs on plants which probably brought them in