Hi,
Yes, report works for classic GL.
Implementing the suggested pre-requisite notes do not have any side impact.
Balances will work for fiscal year also provided fiscal periods start from first day of the month to last day of the month. In SAP all balances are stored period wise.
Example, you have a fiscal year starting from April 2014 to March 2015 this corresponds to Jan 2014 to Dec 2015.
If you have a one to one mapping of fiscal year and calendar year, the reports works correctly.
Example April 2014 is mapped to Jan 2014; May 2014 to Feb 2014 and so on....
Note that the above mapping is just an example, the point is one fiscal period should correspond to one calendar period.