In regards specifically to the scope of one account or opportunity, is there a limited amount of information synced when using the "Sync to Quickbooks" button versus running a datasync session.

I am running some tests, and I have a lot of data cleansing to do, so I dont want QB and Salesforce to completely run right now.  Therefore I have kept Datasync setting to NEVER.  However, for the purposes of testing the integration I am using the only the Sync To Quickbooks.  While the hidden key fields like Transaction TXnID are showing back into salesforce none of the other fields as you outlined in the field sync guide are coming back.

For example in a opportunity invoice set to closed/won, I have pressed the "Sync To Quickbooks" button.  All the following fields DID NOT sync:

Invoice Number, Shipping Address, Billing Address, Ship Method, QB Total Amount, Ship Date, Terms Code......

Please provide clarification.  Thanks

When you use the button, it will only sync that specific record. The Transaction TXnID as well as the QB Transaction Date should return. The others return the next time that the full sync from QB to SFDC runs. So, you will see that information come back but not until you complete a sync from QB to SFDC.