Can my sub-accounts show their own branding instead of mine?

Yes. In Settings, then SaaS Configurator, you can turn on the option that allows sub-accounts to customize their own branding. When it is on, a sub-account can put its own logo, name, email and phone number on its Branding page instead of yours. It is still served from your white label domain, but it looks branded as theirs. Turn the option off to keep your branding on every sub-account.