Zulfa
Yes. Zulfa is based on Arabic poetic vocabulary (زلفة / زلف) and is also used in Persian/Urdu poetic contexts; as a given name it appears in South Asian and Middle Eastern onomastics.
Poetically, yes. The term's metaphorical use in ghazal and Sufi literature links it to themes of spiritual nearness and longing, though the name itself is literary rather than doctrinal.
Common renderings include زلفة or زلفا depending on regional orthography and vocalization.
No. Zulfa is relatively uncommon today and is chosen for its poetic and Sufi-inflected tone.
Zulfa is primarily attested through poetic diction and regional name lists rather than as the name of widely known historical personalities; its usage is literary and onomastic.