Safari SSL Errors
If you've deleted the root certificates from your keychain, the easiest way I know to fix this is to reinstall.
When you visit a website, the browser checks the "chain of trust" of the website certificate. Basically it checks to see who has signed the certificate. If the root certificates are gone it won't recognise any of the common authorities like Verisign, Commodo, etc as being trusted.
Another option might be to download and reinstall a recent OS update from Apple as suggested here https://apple.stackexchange.com/a/123151/4007.