1. Have had them turn off private WHOIS for all (hundreds of) domains "by accident".
2. I haven't figured out a way to export a list of domains after their UI revamp some years ago.
3. At some point they started setting DNS records for newly purchased domains to their landing page with a 30 minute TTL, which makes setting up something on the fly impossible, unless you use their API:
4. Their API is flaky at best. I wrote a script to register domains and set NS records and was forced to write a loop to set NS records up to 10 times until they got set properly.