Sounds like a lot of the same goals of Windows Longhorn. Ironically, .NET Core has made alot of the goals they were trying to achieve more achievable now. Trying to build an OS in .NET in 2005 it was too slow, database filesystem has sort of kinda materialized, but not like the design as I remember it. In my view, the ultimate OS is something that is:
-Modular
-Consistent in API across domains
-Skin-able
Its also interesting to see what MS does offer these days. Powershell returns objects so you can actually get at the a Process object with proper typing instead of dealing using sed to parse out some info.
It can be really nice if you have the time to look up the documentation. It doesn't have the WYSIWYG simplicity of files, though.
