Hi Sidharth,
Please find my 2 cents below 
1. are the column views automatically generated when we create a HANA optimized infocube/DSO or is any other step required?
A1: Yes, ColumnViews are automatically generated by BW for infoproviders such as infocubes and DSOs. They are needed by SAP HANA calculation engine as a "translator" for the entity relationship of underlying tables in HANA database.
2. where are these column views created ? Can we view them in the HANA studio?
Column Views are created in the HANA database under _SYS_BIC