If you're investing much time in this (and it reads like you are) then you need to plan for easy upgrade to 2010 or later. In 2010 only the reporting db is supported for access, which in turn is only updated after a Publish. So, in 2007 create a View in
SQL Server that gets the data you need and read from your code. After an upgrade to 2010 change the View to read from the Reporting db and you're done!
VSTO is not needed, use OLEDB or .net direct. VSTO is only needed for talking to Office clients.
Rod Gill
The one and only Project VBA Book
Rod Gill Project Management