Question regarding no-mixing policy

[pronicoxd]

Snippet from COMPLYING WITH SPOTIFY'S DEVELOPER POLICY

Disallowed Use case:

DJ/Mixes: Using Spotify’s catalog to segue, mix, re-mix, or overlap any Spotify Content with any other audio content (including other Spotify content).

I am playing around with a prototype using both the Web SDK and Web API and this one policy line has me confused unfortunately. The point is for users to be able to make a personalized playlist where each song is played for a specified number of seconds potentially with user-generated voice recordings in between (Not overlapping). I have found this to be a fantastic way to experience music in small social gatherings, but current ways to do this require knowledge about audio/video-editing software and lots of song-purchases to acquire MP3s  (if not resorting to pirating). Therefore I come with a few questions:

Q1: If the audio content does not overlap but is played consequtively, would that be considered mixing? E.g. Playing a voice-recording "Hello everybody and welcome" followed by (Not overlapping) a spotify song playing.

Q2: Allowing users to specify how long they want to listen to each song, and where it should begin (without overlapping any audio content) be considered mixing, or just editing and playing snippets?

Q3: Unrelated to policy-snippet - Would it be okay to allow users to tip the developer for an application?

Kind regards,

Nicolai Grymer