1). Friday, if it coincides with the Day of Arafah, they call it al-Hajj al-Akbar. Whereas, the Day of al-Hajj al-Akbar is the 10th day of Dhul-Hijjah, the day of Eid, when the pilgrims slaughter their sheep, shave their heads, and stone the Jamaraat [Saheeh al-Bukhaaree (3177)]. And it has nothing to do if that day coincides with Friday or not.
2). Friday, if it coincides with the odd nights from the last 10 days of Ramadhaan, then it is a Laylatul-Qadr. Again, no evidence except for the personal opinion of IBN HUBAYRAH رحمه الله (many misread his name as Abu Hurairah رضي الله عنه, which caused some confusion). And what has been attributed to Ibn Taymiyyah is nowhere to be found.
3 ). The Last Friday of Ramadhaan. No special virtue has been reported about the last Friday of Ramadhaan. The last Friday is not different from the first Friday or any other Friday which falls within the month of Ramadhaan.
4). Friday, and greeting each other with Jumuah Mubaarak. Again no evidence! We have been instructed to prepare for the Friday prayer by taking a bath, putting on fresh clothes, using perfume before coming for the Friday prayer, to recite Surah al-Kahf, to invoke more blessings for the Prophet ﷺ on this day, to make Duaa (between Asr and Maghrib) etc., but nothing reported about greeting each other with Jumuah Mubaarak. Shaikh al-Fawzaan and others have spoken about this already.
Some Ahaadeeth on the virtues of Friday:
Abu Hurairah رضي الله عنه reported the Messenger of Allaah ﷺ as saying:
❝The best day on which the sun has risen is Friday; on it Aadam was created. on it he was made to enter Paradise, on it he was expelled from it. And the last Hour will not be established except on Friday.❞
[Saheeh Muslim]
Aws ibn Aws رضي الله عنه narrated: The Prophet ﷺ said:
❝Among the most excellent of your days is Friday; on it Aadam was created, on it he died, on it the last trumpet will be blown, and on it the shout will be made, so invoke more blessings on me that day, for your blessings will be submitted to me. The people asked: O Messenger of Allaah! How can it be that our blessings will be submitted to you while your body is decayed? He صلى الله عليه وسلم replied: Allaah تعالى has prohibited the earth from consuming the bodies of Prophets.❞
[Sunan Abu Dawood (1047) and graded as “Saheeh” by Shaikh al-Albaanee]
Narrated Taariq bin Shihaab narrated: A Jew said to Umar Ibn al-Khattaab رضي الله عنه: “O Chief of the Believers, if this Aayah: {This day I have perfected your religion for you, completed My favors upon you, and have chosen for you, Islaam as your religion.} [Surah al-Maaidah (5): 3] had been revealed upon us, we would have taken that day as an Eid (festival) day.” Umar said: ❝I know definitely on what day this Aayah was revealed; it was revealed on the day of `Arafah, on a Friday.❞
[Saheehain]
وَمَا تَوْفِيقِي إِلَّا بِاللَّـهِ ۚ عَلَيْهِ تَوَكَّلْتُ وَإِلَيْهِ أُنِيبُ
English 
