This may be too complicated to address here but thought I'd throw it out to some of those who have experienced this.

We have a current instance of NetSuite that was customized in an awful way (to the point of so many customizations and scripts to normal records like cases and customer records that we can't cleanly build an appropriate new implementation). This is a production environment.

We are building a completely new design on a clean instance of NetSuite and want to make this the production environment moving forward, however, at a minimum, we will need to move financial data over. Problem is we do not want to move over anything that has the bad customizations (e.g. sales orders for one).