Public Trust identity validation for a German sole proprietorship (Einzelunternehmen) without commercial register entry

I am a software developer based in Germany, planning to code-sign a Windows desktop application for distribution both through the Microsoft Store and directly to customers.

My legal form is a German sole proprietorship (Einzelunternehmen with Gewerbeanmeldung). It is a registered business with a tax number and VAT ID, but it is a natural person and is not listed in the German commercial register (Handelsregister), which is normal and legally correct for this business type in Germany.

From the documentation I understand that:

• Individual identity validation for Public Trust is limited to developers located in the USA and Canada, so this route is not open to me.
• Organization identity validation for Public Trust is available in the European Union, which includes Germany.

My questions:

1. Can a German sole proprietorship without a Handelsregister entry complete Public Trust organization identity validation?
2. If yes, which documents are accepted as proof of the organization? I have applied for a D-U-N-S number. Is that sufficient on its own, or is a commercial register entry required in addition?
3. The billing account type must match the validation type. For a sole proprietorship, should the Azure billing account be created as an organization/business account even though the legal entity is a natural person?
4. The certificate subject uses the validated legal name. For a sole proprietorship, would this be my personal name?

I would like to confirm eligibility before creating the Artifact Signing account, since I understand that the number of validation attempts is limited and I want to avoid a failed onboarding.

Thank you.