Quoting from the Spotify for Artists FAQs page, "Spotify is an open platform for artistic expression. We believe in everyone’s right to share their voice. So generally, all creators and content are welcome on Spotify. However, in the scenarios outlined below, content may be removed or filtered from Spotify".
I think that spoken tutorials would fall under the "podcast" category, so this FAQ page will be your best shot: "Sharing your podcast on Spotify gives you access to millions of Spotify listeners in 60 markets across desktop, Android, and iOS devices. If you host your podcast with one of our aggregator partners, you can easily submit your podcast to Spotify in minutes".
Unfortunately, I don't have the answers to those questions, you should contact your label or distributor, they will be able to inform you about the royalties.
If you want to get more information about podcasts on Spotify you should check the Spotify for Podcasters webpage, they have a FAQ page and they also have a contact form at the bottom of the page, that way you can contact them if you don't find the answers you're looking for.