Pls find my reply..

Does the report have to run during business hours? - Yes

Can the report be scheduled to run outside of hours? - No, because the end users needed the report as soon as they update/change the data

How often does the report need to be run? - 20-25 times within the business hours

Does the user need to input parameters to run it? - It Depends, but not necessarily.

Has the background query / SP's been performance tuned? - Tried as much as we could. The SP uses few remote queries and lot of temp tables. Tempbd is in separate drive only.