Another update here.
After some communication with Thomas Jung in this thread,
http://scn.sap.com/thread/3371514
The appearance of Content folder is just as simple as setting up Customize View in HANA System/Navigator. Quoting Thomas,
In the SAP HANA Systems view/Navigator, click the triangle in the upper right corner. Choose Customize View. On the Content tab, select the Content folder. Then you will see the Content folder in your hierarchy.
So far my HANA Developer system on AWS is running well with below combination,
Client Rev 48 - Studio Rev 48 -> connected to HANA Developer Rev 56
Regards,
Idi