2. Why is that an issue? Upload videos of yours and provide links, show them scripts. Provide a CV. Portfolio could be a list of videos you have produced, for which clients, etc.
3. No, you can have something else. You are a micro-entrepreneur? Get a "Certificat d'inscription au Répertoire des Entreprises et des Établissements (SIRENE)".
What is the accountant supposed to guarantee? Maybe explain in a letter that you do not have to hire one from a legal perspective and provide something else as a replacement. Tax returns? Have your tax returns notarized?
The TDAC is for everybody. You don't have to complete it 3 days before your departure date. You have to complete it up to 3 days before your departure date.
Participant(e) anonyme You're in China, right? You have been stamped in when entering its territory, right? If THIS stamp is in your previous passport, you should have sent both scans, just to be sure. There's nothing you can do now, you can only wait. Maybe they will be fine with the current passport only, maybe they wanted to see your entry stamp, there is no way to know for sure. That's why uploading both would have made sense (if your CURRENT CHINESE ENTRY STAMP is in your old passport).
Participant(e) anonyme Does it contain your current Chinese entry stamp/visa? If yes, it would have made sense to upload a scan of it. However, you cannot upload anything if there is no request for additional documents. If you've done the upload already, the only thing you can do is wait for them to either issue/deny the visa or request further documents.