To answer your follow up questions:
Tiger65: Can the Transaction Sync period be reduced selectively going forward?
You can adjust your transaction history at any time by going to the syncronization page and changing the settings. If you shorten the range, transactions outside of the range will be hidden in Method.
Tiger65: Can QuickBooks Pro be upgraded at some future time to Enterprise without starting over with Method?
You can update to Enterprise at any time. Method connect to the company file and finds the records based on the QuickBooks listID. These listID's won't change when you switch QuickBooks versions.
Tiger65: Since we are in the testing phase with an older datafile copy, can we switch to the current production datafile without starting over?
You may have to start over. When Method connects to a company file, it creates a one to one relationship with that file. As I said above, Method associates each record with the ListID in QuickBooks. If you were to switch to a different file, the ListID's would be different. For example, CustomerA in the old file will have a different ListID than CustomerA in the new file, even if they have the same information. Method would not be able to find the records in QuickBooks and this will cause conflicts and errors.
If you do switch to a new file, we can do an account reset that will wipe the account as if it were a brand new account. All data and customization will be lost. You could then sync the new file to the Method account.
Hope this helps,
- Adam