If the edo tensei had unlimited chakra, couldn't they use the rinne rebirth on themselves without risks?
Simply put, the Rinne Rebirth Jutsu uses the user's life force to breathe life into another body. The user of this Jutsu inevitably dies after the completion.
An Edo Tensei reincarnation is just soul and chakra bound to a body. The soul is bound until the contract ends and the chakra is limitless.
(Thanks to @Henjin for pointing it out): Since the Edo Tensei reincarnation does not have life force within them, they wouldn't be able to perform the jutsu.
But, considering the possibility that they have unlimited chakra and the life force requirement is overlooked, this situation would become a paradox. The user has to first deplete his life force and die, to bring himself back from the dead, all while being a reincarnation. This would mean the user wouldn't be able to complete the Rinne Rebirth jutsu, because of the limitless chakra and contract.
(note: this question sides on the "opinion based" area. But I've tried answering with the facts from the series)