Altought Tryton correctly calculates both reports it is not possible to export both of them as a Printable Format (ODT or PDF).
This two reports are usually used to analyze the status of the company and they are often required by external entities. For example a bank when then company want’s to request a loan. For this reason I think it make sense to have a default print format to generate them.
In order to print this report we shold activate the print action on the Balance Sheet and Income Statement actions. I think both actions should print the full tree structure and do not require to mark all the records because it does not make sense to have any of this reports with the full structure. It should also be possible to print the amount and the comparision amount on the report. Last but not least, in order to be able to identifiy the context values (company, date, fiscalyear, etc.) used to print the report they should be printed on the header.
About the format I think we should use a generic format following the styles of the standard accounting reports letting the user customize the report to match it’s own style.