I branched this as its own question because it's very different.
The location of the ScheduledTriggerViews doesn't matter as it's only a configuration file when a VA (VizAlert) is triggered. I have mine in an admin Site but my other Sites still run VAs. You only need one ScheduledTriggerViews so don't worry about which Site contains it because that doesn't matter. Remember, VA pretty much works like the standard subscriptions; the Schedules are shared across all Sites.
As to your particular request, using an Excel file to divvy out reports to various Sites, I don't think your idea will work. You'll need that Excel data source in each Site. One good thing is that you can have the single Excel data source on a network drive and publish it as a data source to each Site, thus one file feeding multiple Sites. For the reports on each site, I'm guessing you'd create a simple calculated field that you use as a filter to exclude data entries in the Excel file that are not relevant to the Site in which the report is running within.