At present their is no Interest calculation in NV2. You need to add it to your accounts manually. An Interest script will be added to NV2 soon.
To generate Customer Statements within NV2, block the Customers in NewViews > Account > Accounts Receivable (Blue table) and either right mouse click on the blue table Print > Statements or use the key strokes Alt PS. Fill in the prompts as required and select a suitable template.
Information about printing customer statements can be found in the NewViews 2.08 manual by Selecting Help > Manual and selecting Printing > Printing Documents > Printing Customer Statements.