I am not all that sure that it should be the candidate himself that should be able to pick and choose what personal information to release. Instead, there should be a standard template that each candidate should complete. Withholding from certain questions would indicate that the candidate is hold back on some information.
This is something that the GOP could have insisted on at least 2 years ago but they were too busy on the golf course and wining & dining each others --and fundraising. Especially the latter. SOBs.