Out of curiosity, why would you want to uninstall it? It's one of the big selling points of the WP8.1 platform and will probably become more deeply integrated as time goes on.
From my observation it only seems to cache stuff when you browser around in it. I have about 80 GB of data in mine and my phone has 95 MB associated with OneDrive.
I love being able to access every file I have from every device I have without even needing to worry about syncing.