How do I obtain and then sort Add/Edit Multiple List Entries (non-inventory items) by historical activity? Thank you!

The Add/Edit function is a way to see your List Elements, such as all Items or all Vendors or all Customers, then be able to work in the List view. Instead of Edit one at a time, you can use this to see and make updates as a table function.

It has nothing to do with transactions, financial activity, on hand, purchases, etc. It's the Name or Label part, such as Widget vs Gadget. It's the Setup, such as flows to Inventory Asset, COGS and Revenue, or Not those same three accounts.

Noninventory items are like other List Elements in that you can run a Report on them. For instance, a QuickReport on one item, set the date to ALL, to see all activity. Filter on posting Status = Either, to see both NonPosting (Purchase Orders, Sales Orders and Estimates) and Posting (invoices, checks, credit card charges, sales receipts, bills) where that item has been used.

There is no one report that simply shows "last date of activity."