Refreshing Excel Web Part connected to SSAS, and requirements?

Scenario: Excel file, with a SSAS data source connection

Pivot Table/Charts with filters and slicers

Published to Sharepoint 2010, such that users can access the report as a Excel Web Access Web Part, such that they can't break/change the pivot table other than changing filters and slicers.

Note that I am NOT talking about powerpivot. Rather just using a regular data source connection.

As users access the report, I would like the most current data(within the last day) from SSAS to be reflected in the report. Assume that the SSAS database is refreshed daily already.

1) Does Excel Services and/or the webpart automatically refresh the data when the report is opened/viewed through the Web Access Web Part? And/or can it be configured to periodically refresh the data?

2) What are the server software requirements to support this? Does it require SQL Server Enterprise edition? Or is standard enough? Does it require Sharepoint 2010 Enterprise, or is standard enough? when I say "support this" I mean both the Excel Web Access Web Part as well as the refreshing of the data from SSAS into Excel.

3) Does the Web Part allow them to only interact with filters/slicers? Or will they be able to mess with/break the pivot table? If so, will changes/breakage they make only be persisted for their session and not effect future sessions or other users?

I would test this myself but I have had difficulty getting the trial of Sharepoint setup on my home computer(ultimately I won't even be the person setting it up in production anyways) and I just want to know what edition will support these features. Thanks.