1- After its death in the Sunni World, the Greek philosophical tradition flourished in the Shia World and became very popular among some famous theosophists. On the other hand, Sufism was better integrated in the Sunni than in the Shia world. Although it was well integrated, the Sufism was about to get suppressed, but fortunately, it survived.
2- I found interesting that the Sufi orders were separate into two categories. The moderate mystics were strict about Islamic Law and its procedures. On the contrary, the other group of Sufi was not really giving importance to introduce the Islamic Sharia but they did not deny it.
Source: Dadfar, S., & Radeh, G. (2016). Role of Sufism in Spreading Shiism at Kermanshah. Journal Of History, Culture & Art Research / Tarih Kültür Ve Sanat Arastirmalari Dergisi, 5(4), 235-246. doi:10.7596/taksad.v5i4.600