The first of your questions concerns the active and passive constructions.
This:
simply means: Is anything different? ‘Change’ is used here in the active form because ‘change’ means ‘become different’.
‘Has something been changed?’ is the passive and it is understood that you are asking: Has something been changed by someone?
‘is changed’ is the present simple passive and ‘was changed’ is the past simple passive.
‘Out of the office’ suggests you are away from the office and possibly working in another place.
‘Out of office’ suggests that you no longer hold a particular post to which usually you have been elected. The president/minister/councillor is out of office means he longer hold one of these posts.