Windows will more than survive on corporate and enterprise licenses purchased by the thousands daily. The integration of their cloud services like SharePoint into mass subscriptions of office 365 is enough for Microsoft to not care about some niche influencer market. Besides multimedia editing software was always dominated by Apple which Microsoft specifically brought back from bankruptcy specifically to avoid an anti-trust case. They don't want that corner of the market and never have.
Linux desktops will never be able to take over unless corporations start installing it for all of their employees. Which again is unlikely considering large corporations don't like change especially in their revenue.
Exactly. They just need to put their standard price per teir on the main website page and add a field for us to put in our address that shows all applicable fees for our area. They can use a mirror of their billing database to eliminate the hard part. The rest is easy.