I am using a MyBookLiveDuo, which is the generation before the MyCloud. It is nearly identical in many respects. I have an OpenVPN server installed on the MBL which i can connect to remotely and then browser my files exactly as if i were on the home network. I have also installed ownCloud server on it which is exactly like Dropbox functionality except that the data is on my own server and not on some third party’s server (like Dropbox is).
You can look at these solutions for yourself. There are guides writtten on this forum for intalling both packages i mentioned on a MBL. At the moment no user has written an install guide for the MyCloud, since it has only been on teh market for a few months. If you have same basic Linux skills you can modify the guides for your device or you can wait until someone else does it. Or if you are impatient, buy a MBL and use the existing guides.