Can Blender manipulate remote assets, without me having to download them to the client machine manually? I have the opportunity to produce some educational videos leveraging an entertainment company's branded characters. The educational course will be delivered online and students will be using Blender installed on their own machines. Can anyone tell me if it is possible to have students use and manipulate these branded character assets within Blender, without ever actually downloading the assets to their machines?
Not directly possible, Blender needs its data to be local (it does not understand uri, FTP, etc.).

You could set up a 'fake' local file system on your students' machine, though, which would actually be a network one (like a samba/windows sharing, or other similar solution). It will work as long as Blender can see it as a local directory.