Yes it would be possible for everything except for Music, Animation and Shaders (because there's no way to create any of these from anything except a file on disk or possibly using file-blocks from the enhancement packs).
It'd be slightly easier to use banks for this purpose:
1. You can map a whole file into a bank with a single command
2. You can copy whole sections of a bank into a memblock with a single command.
Beyond that, you could store the 'memblock' format of the media for images and sounds, and objects can either be stored in DBO format or your own custom format - there are enough commands in my plug-ins that you can quite literally build an object from scratch, as long as it's not animated - if you want animation, use DBO.
... Or you could buy the enhancements pack