Skip invalid SSL warning and show detailed errors in Safari

I have Safari 12.0.3 and couldn't find two settings:

1. Sometimes I need skip invalid SSL warning for self-signed SSL or expired SSL.

I would like to skip the warning without adding the certificate to keychain, as I do in Chrome.

Is it possible?

Please don't tell me I shouldn't as I know what I'm doing.

2. I tried to check an issue with a website. I couldn't see the actual errors in Safari. When I switched to Chrome, I saw detailed PHP errors immediately.

Is there a setting like " disable friendly HTTP errors" in Safari?