RSS/Atom feeds and video files you can play with whatever video player you want seems like it'd cover most of those concerns? The relatively closed nature of YouTube isn't necessarily something you'd want to replicate.
The bigger issue would be search and discovery, especially since I can't think of any obvious way to prevent services from spoofing engagement data to influence rankings.
The bigger issue would be search and discovery, especially since I can't think of any obvious way to prevent services from spoofing engagement data to influence rankings.