Pick a look and every scene follows it, from a messy whiteboard to a sumi-e wash. Or upload your own reference.
Yes. Pick a different style and the video is redrawn in it. The script and the narration stay as they were, so only the look changes.
Yes, that is the point of choosing one. The style is a setting applied to the whole video, so scene twelve matches scene one and a series of videos looks like a series.
Blueprint and minimal read as precise and technical. Notebook suits worked examples and maths. Whiteboard and chalkboard are the neutral defaults that fit almost any subject.
You can upload your own reference and have the video drawn to match it, which is what people do when the look has to fit an existing brand.
No. The style affects how each scene is drawn, not how much there is to say, so length follows the script rather than the look you picked.