Hi! It might be a bit late, but in case you still need help, here’s what worked for me:
My legal name is different from my creator name on Zazzle, and I haven’t had any issues with that.
I’m not sure if using different emails for Zazzle and PayPal would cause a problem, but I used the same email for both, so I’d recommend doing that if possible.
Yes, the W-8BEN form can be completed digitally, and you can use a PDF editor for the digital signature.