conrado, regarding your #2 item. Assuming MS Windows, this is already solved by the OS. Say it is a Word file, and you decide to save it in the same place as the one you already had, MS Word won't let you save with the same filename. Thus you have to rename it to something else and the onus would be up to you to not forget that you renamed it.
But florut said: "So Fx renames it automatically as 'document(2).doc" but I don't know what "Fx" is. Is that a word processing program? Perhaps it tells you that there's already an existing file with the same name? Most programs don't usually automatically rename files, and if they did I understand how that would be confusing. MS Word does not do this, perhaps there is an option to turn it off in this Fx program.
cheers