1a) Reports, Lists, Accounts -> This is not date sensitive

1b) Reports, Financials, Trial Balance -> Date sensitive

2a) Unlink and delete is possible but it depends on what you are trying to delete.  Setup, Settings, pick your module on the left, Linked Accounts, select the account and hit delete.

If you are trying to delete an accounts that has entries either last year or this year, you will not be able to delete it.  Note I did not say has a balance.  It could have a zero balance but if there are entries, they will not be able to be deleted.

2b) I would pick this option before deleting.  See the images below.  I choose the first one most of the time as there are some accounts I want to see a zero balance if there is one on the financials.  I rarely delete accounts if I think I may use them as the company will evolve and need them in the future.  I've seen someone delete all payroll accounts, only to hire me to put them all back again a year later when he decided to hire employees.  But it depends on the company and its purpose.

Image 1: Omits select zero balance accounts -> Company, Chart of Accounts, open the account ledger

Image 2: Hides all zero balance accounts -> Reports, Financials and either Balance Sheet, Income Statement, Trial Balance and Multiperiod reports if you are using Premium or Quantum.

1a) Reports, Lists, Accounts -> This is not date sensitive

1b) Reports, Financials, Trial Balance -> Date sensitive

2a) Unlink and delete is possible but it depends on what you are trying to delete.  Setup, Settings, pick your module on the left, Linked Accounts, select the account and hit delete.

If you are trying to delete an accounts that has entries either last year or this year, you will not be able to delete it.  Note I did not say has a balance.  It could have a zero balance but if there are entries, they will not be able to be deleted.

2b) I would pick this option before deleting.  See the images below.  I choose the first one most of the time as there are some accounts I want to see a zero balance if there is one on the financials.  I rarely delete accounts if I think I may use them as the company will evolve and need them in the future.  I've seen someone delete all payroll accounts, only to hire me to put them all back again a year later when he decided to hire employees.  But it depends on the company and its purpose.

Image 1: Omits select zero balance accounts -> Company, Chart of Accounts, open the account ledger

Image 2: Hides all zero balance accounts -> Reports, Financials and either Balance Sheet, Income Statement, Trial Balance and Multiperiod reports if you are using Premium or Quantum.