Thanks for reaching out!
To be able to get a wide shot of a 10m wide stage and a medium shot of a person from 65' away you will need a lens that is around 30mm on the wide end and 280mm on the telephoto end. Unfortunately, there are no Micro Four Thirds lenses that cover that entire range.
The only lens that comes close is the Olympus M.Zuiko Digital ED 12-200mm f/3.5-6.3 Lens(Affiliate link). It will also need a 1.4x teleconverter paired with it to give you enough zoom for a medium shot, basically giving you a 17-280mm lens, which will also cut down the amount of light going into the camera. And that lens already gets pretty dark at the far end of the zoom (f/6.3), so it will not be the best option unless you have quite a bit of light.
Also be aware that lenses like that will not give you smooth motorized (servo) zoom capability. The will be manual zoom only, so any zooming you do while live streaming will be rather jerky and potentially distracting.
In this situation your best bets will either be a camcorder or adapting to something like a Canon EF lens.