Can Rise 360 courses be downloaded/shared as mp4 file?

Phil's suggestion would work for a Rise course. In addition to a good microphone, you'll probably need to practice any narration. Or plan on editing shorter recorded clips together.

Since you know you need an MP4, I think it'd be better to develop in Storyline. A .story file can be exported as an MP4. You'd have exact control over the timing of each slide, and you could use text-to-speech for narration.