DropBox as a root folder
We generally do not recommend using a dropbox folder for placing your files as dropbox's rsynch like behavior can cause file corruption. We understand that a number of blogs have suggested this but we have noted issues and do not recommend it.
In addition (and more importantly), please note that most hosting providers do not use Mac OS X and home folders usually follow a Linux like convention for permalink-like friendly root paths (lowercase alphanumerics, hyphen and underscore okay). This is important as WordPress itself does store the root folder in various locations (i.e. 'recently_edited' values, along with plugins the do the same). The occurrence of spaces, punctuation and in particular, brackets and parenthesis in a folder path are not acceptable and can prevent normal WordPress operation. For maximum compatibility, please use a document root folder with a path that follows the safe permalink-like convention.