For #5 I believe it's not just a self-XSS, but also executes on the support agents browser, allowing you to potentially exfiltrate their cookies:
> Anyone can write malicious code into the chatbox and PayPal’s system would execute it. Using the right payload, a scammer can capture customer support agent session cookies and access their account.
> Anyone can write malicious code into the chatbox and PayPal’s system would execute it. Using the right payload, a scammer can capture customer support agent session cookies and access their account.