#1, good call!
#2, usually I am 100% in agreement. But referer vs referrer in the HTTP spec is a special case. I chose to do this as referer is misspelled in the spec itself.
As a user, I’d rather have a failure at boot time if I got it wrong. Just because I had a typo once doesn’t mean I always make it. What if I tried to transform my own config? I’d have to follow special case your referers property like you did to keep it consistent.