Should I shorten and combine the Thuhr and ‘Asr prayers on the day of ‘Arafat while performing the prayers in my tent, not in Namira Mosque? What about the Sunnah prayers; should l perform them during the stay of Hajj?

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.

It is a Sunnah for you to combine the Thuhr and ‘Asr prayers at the time of the Thuhr on the Day of ‘Arafah, even if you are not praying at Namirah Mosque. Combining the prayers is a Sunnah for every pilgrim in ‘Arafah. The Hanbali book Daqaa-'iq Uli An-Nuha Ma’a sharh Muntaha Al-Iraadaat reads:

“Not combining the prayers is better than combining them as a way of avoiding the difference of opinion, except for the combination of prayers at ‘Arafah and Muzdalifah, as it is a Sunnah, if this condition is available, to combine (in 'Arafah) the Thuhr and ‘Asr prayers at the time of the Thuhr, and to combine in Muzdalifah the Maghrib and ‘Isha prayers at the time of ‘Isha.”

During Hajj, you should perform as many Sunnah prayers as you can, especially the Rawaatib (i.e. confirmed or unconfirmed supererogatory prayers that are performed either before or after the obligatory prayers), as one should perform them even while traveling according to the view of most of the scholars, let alone for a person who is performing the rituals of Hajj; An-Nawawi said:

“Our scholars said, 'It is desirable to pray the supererogatory prayers during travel, whether the Rawaatib related to the obligatory prayers or otherwise: this is our view and the view of Al-Qaassim ibn Muhammad, ‘Urwah ibn az-Zubayr, Abu Bakr ibn ‘Abdir-Rahmaan, Maalik, and the majority of the scholars.' At-Tirmithi said, 'This is the view of a group of the Companions, Ahmad, Is-haaq, and most scholars. But a group of the scholars said that one does not pray the Rawaatib prayers while traveling.'”

Allah knows best.