Are the Hadiths mentioned concerning the virtues of Surat Al-A'raf authentic, or are they fabricated? And are there any sound Hadiths reported regarding its virtues?

There is no established specific virtue for Surat Al-A'raf, and the narration reported from Ubayy ibn Ka'b concerning its virtue is a fabricated hadith by agreement of the memorizers of hadith. Likewise, the reports attributed to Ja'far al-Sadiq regarding its virtue are weak Shiite reports. Rather, the virtue that applies to it is that mentioned for the Seven Long Surahs, as in the hadith of Aisha: "Whoever takes the first seven surahs, he is a scholar."