What is the ruling on the two rak'ahs of tawaf after 'Umrah, and are they independent or do they fall under the Sunnah of the obligatory prayer, and what is their ruling if the tawaf is after the 'Asr prayer?

The two Rak'ahs of Tawaf are a confirmed Sunnah according to the majority of scholars. If a circumambulator prays the obligatory prayer after his Tawaf, scholars differ on whether it suffices for the two Rak'ahs of Tawaf or not. The more prevalent opinion is that it does not suffice. As for praying them during forbidden times (awqat an-nahy), the more prevalent opinion is that they can be prayed during forbidden times, contrary to the views of Abu Hanifa and Malik. A number of Companions and Tabi'in did indeed do so.