Should I be concerned that my https with https://news.ycombinator.com started wigging out after I posted the original question? Chrome wouldn't load it due to safety concerns
Yes, that does sound concerning, though it doesn't necessarily mean anything in particular. If you do get an invalid cert for HN again, please consider posting the fingerprint and CA, etc.
Have never experienced that before, continued for about 5 minutes after I posted and occurred almost instantly after I posted the question (I tried to make an immediate edit and chrome blocked it because of the https issues).
Do you use any certificate-related extensions? If not, you may want to install one that compares certs to those seen by others, just to see if anything interesting occurs. Also, check for any unexpected trusted CAs. I've seen a system infected by malware that adds a CA that was signed by a leaked Microsoft key.