Hi Benedict,
I would try to answer it as per my understanding:
1) I tried creating a column view using SQl and I see the column view under the 'Column View' folder. But I am not able to use this column view anywhere.
When we create any Analytic View, Calculation View or Attribute View then a column view is created for them in _SYS_BIC schema.
So if you have created a column View then you can use it in reporting - try to open this view using MS Excel.
2) i tried creating a view by right-clicking on the 'View' folder, but I could only save it as a local .vsql file. What purpose do this serve?
This View is your SQL View - a virtual table in which you combine tables and can filter data that you want and then you can perform operations on it.
You can create SQL Script based Calculation Views using SQL Views