the motivations are clear (a Nazi hatred of Jews and a complete lack of fear from a Jewish response).
a few known leaders are the imam of Lod Yusuf Albaz, Kamal Khatib the deputy chairman of the northern faction of the Islamic Movement, Hamed Abu Daabas (the chairman of the southern branch of the Islamic Movement and the spiritual leader of the United Arab List, a party now in the coalition), Said al-Harumi from the United Arab List, Muhammad Mahameed the leader of the Islamic Movement in Yafo, Ibrahim Sarsur a senior leader in the United Arab List, Ayman Odeh of the Joint List. but the Intifada was a spontaneous, from bottom to top popular national action supported by Arabs of all factions, not driven by the leadership of any specific leader.
there is no question though that foreign entities (Turkey, Iran, Qatar as well as Egypt, United Arab Emirates and Saudi Arabia) were deeply involved in supporting the different factions involved in the Intifada whether by the means of funds or arms or both. the EU had a role as well. here is a screenshot from Albaz's facebook profile (it is well known that Turkey supports the Muslim Brotherhood all over the world including in Israel, and Albaz belongs to this movement):
Arabs in Israel (Muslim, Christian and Druze) are a fifth column, proxies of foreign entities.