Hi,
well, ok so can i change the file label from the template? i mean form inside the php? without loosing functionality?
No, this is not possible (see screenshot)
have another question, this might not have the correct topic: what is the difference between a field that has CORE enabled to another that does not belong to the core? Like advantages and disadvantages
Core status is only a information, all core fields are required and you cannot change status (for example you can't unpublish). You cannot change core attribute.