ISU shouldn't be surprised when there are two people in the audience. I'd 100% go if I knew I'd be able to get tickets and the visa in time. The final is such a fun event, shame that China isn't promoting it.
Cityline.com works. Don't need China passport or phone number. It's a HK website, so you can even opt for English version. Should be legit as this is the ticketing website the China Figure Skating Association directed me to when I emailed them.