XtraReports 10.1.7

I would like to use SPs for all data retrieval for over 100 reports, many involving parent-child and even grandchild relationships and using detail bands rather than subreports.

I have a lot of questions, so bear with me and I'll be very grateful.

In VFP,  we were mostly limited to one detail band and the common practice was to flat-file the data and use grouping.

It looks like XtraReports, offering multiple detail bands, is happiest with actual parent child relational data, just as we would pull it for CRUD.

I love the idea of pulling all data for a report with one SP.  I send params defining set of parent records and use the list of pks of the selected parents to pull all relevant children - all in one trip using fullmultipledatatables().  ( in actual CRUD, of course, I usually just pull one parent at a time with its associated children, but in reports it would seem multiple parents and filterchildrecords() would be more common )

My first big decision seems to be : BOs or datasets or datasets filled from BOs

My main concern is how to have the structure available at design time for laying out the reports. 

If I'm just going to use the standard ADO stuff, I see I can use the dataexplorer in VS2010 and pick the sp as a datasource.  But it seems only the first table of a multitable sproc will get its structure into the treeview.  Is there a way to have the structure of a multitable sproc populate the treeview?  I would certainluy like to avoid manually designing each datatable in the dataset for each report.

If I use BOs, using fillmultipledatatables, can I see their structure at design time to design my reports? 

Do I need to make the child bos properties of the parent as in the RSS example ?  Wouldn't filterchildrecords() work?

Does XtraReports see a SF BO as an iList object?  What is the best way to handle SF BOs in Xtrareports?

I have considered the best way might be to use SF to deal with the sp, fill multiple BOs and then just grab their data at run-time to populate the dataset I will past to the report object, but that still leaves the question of design time what do I use for data in the designer when telling the report controls what they will be bound to?

I'm sure there is a lot more to ask but perhaps Peter and Bill and others who've been down this road can clear up some of my thinking so I can ask more intelligent questions on this.  I'm starting a really big project with it and I want to resolve some conceptual issues before going to far in the wrong direction

Thanks in advance