Excel's Worksheet Password Protection

I use Excel’s worksheet password protection to lock cells with formulas so that users do not accidentally delete formulas. Is it necessary to do this when using XLS Padlock?

Does XLS Padlock lock the cells marked as “locked” on Excel’s format screen to prevent accidental deletion on the contents or does it just obscure the actual formula?

You can lock cells but it is not really necessary to lock the ones that are protected with XLS Padlock’s formula protection. Note that it will just obscure the actual formula (replace it by a built-in function).