Event viewer will always have errors, they aren't often relevant.
Systems running fine will still have them, some like
"The previous system shutdown at 6:58:42 AM on 12/8/2016 was unexpected" could just happen if you unplug PC after turning it off , I expect
"The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly." was an Event 41, which is a result of a report windows runs every start up to see if previous shutdown was normal
You’re sure to see some errors and warnings in the Event Viewer, even if your computer is working fine.
The Event Viewer is designed to help system administrators keep tabs on their computers and troubleshoot problems. If there isn’t a problem with your computer, the errors in here are unlikely to be important. For example, you’ll often see errors that indicate a program crashed at a specific time, which may have been weeks ago.
http://www.howtogeek.com/123646/htg-explains-what-the-windows-event-viewer-is-and-how-you-can-use-it/
As for your problems, I would check you have latest drivers for motherboard and any USB devices as its more likely to be drivers than Win 10.