Opening files actually mean downloading the file (in the background from the browser's perspective). However we are planning to add built-in viewers for most file types so that we can separate Open and Download actions. For instance, we recently added Media Player which can open video and audio files directly and not via browser. In the next version, we plan to add viewers for common document formats like Word, Excel ,PDF etc. So it will be possible to allow users to Open and Print only when required. We will also have 2 separate permissions like "Preview" and "Download".