Can I put my logo on albums, or is that a white-label premium thing?

Logos are available right down to the free plan — no premium tier needed. Every album can show your logo, and you've got two levels of control: per-album (use the logo from your profile or upload a fresh one just for that album) and account-wide defaults set in Album Defaults. So your studio logo appears on guest pages by default, and you can override per album when a client has their own branding requirements.