Can I whitelist domains that I never want to be blacklisted?

Yes. You can whitelist domains by visiting https://dnswatch.watchgaurd.com/domains/whitelist/.

DNSWatch can never blacklist anything on the Alexa 100 (the most common websites on the Internet.) The DNSWatch team also maintains a global whitelist that we carefully manage in case a legitimate domain is added to one of the feeds we consume.