While providing Pashupatastra to Arjuna Lord Shiva says that neither chief of Gods nor humans know of it. So, it is not possible that any other human would have Pashupatastra. From Vana Parva of Mahabharata:
ददानि तेऽस्त्रं दयितमहं पाशुपतं महत् |
समर्थो धारणे मोक्षे संहारे चापि पाण्डव || १३ ||
नैतद्वेद महेन्द्रोऽपि न यमो न च यक्षराट् |
वरुणो वाथ ...
No, there is no time travel involved. It just just that Shri Rama descended on earth multiple times, one of them being at the time of Sati. Below we will discuss the timeline of the current Svetavaraha Kalpa.
Firstly let’s see, Sati’s timeline. Daksha was born in Swayambhuva Manvantara of current Svetavaraha Kalpa (yes current unlike what is ...