i would like to suggest having batch delete option for all tabs.
this would be helpful for users in many ways. following are what came up in my mind.
when a business would like to start fresh for a new financial year, they can just create a copy of the business file, import it and delete all the transactions. this would help keep all their settings and COA.
most tabs which do not affect the financial status of a business can be cleared of old junk every financial year. an example would be the sales quote tab.