Answer
(Fatwa: 873/B=155/TB=1433)
(1) According to Hanafi Fiqh it is wajib to offer three rakahs witr salah with single salam. If any Imam leads witr salah with two salams in Ramadan then the salah of Hanafi shall not be valid. Hence a Hanafi should offer his salah separately.
(2) Yes, the salah of that person shall be valid. Since people nowadays are not aware of the rulings, so if the person who comes after the first saf (row) is complete and he pulls someone from the saf then he does not come. Hence now the fatwa is that he should stand alone in the saf without pulling any one behind. His salah shall be valid without any karahah.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband