bro L.Hu,
Ok so let me try to answer your questions, or at least give my opinion (since I have a breather for a day or two).
Umayyads as equal to prophets:
1) It is true that early Khulafaa were considered political as well as "religious" (I'd rather call it spiritual) authoritarians, I highly doubt they considered themselves equal to prophets. I mean "divine" (or transcendent) inspiration is a basic tenet of TaSawwuf (Sufiism). My own grandfather had allegedly written down the time of his natural death long before he died; how much of this is fact and how much is fiction, I don't know. It was prevalent in many other circles in Arabia and the Fertile crescent (exhibits are the apocalypses of various Christian and Jewish religious figures). Did all these people consider (or allege) themselves prophets or equals to prophets? Doubtful generally speaking; we do have exceptions in case of the person we have come to know as Muhammad, and others being Musailmah etc.
2) If indeed Umayyads considered themselves equals to prophets, then why would the Dome of the Rock read "You (God) bless Muhammad Your servant, Your prophet, and that You accept his intercession for his people, the blessing of God be upon him and peace be upon him and the mercy of God". This portion of the inscription does not belong to the amendment made by Mamum ur Rashid, and is the most likely the original inscription from the time of Abd al Malik bin Marwaan.
3) Was Quran considered secondary (or as equivalent to other edicts) at this point: Likely, since the concept of intercession by the prophet is NOT A QURANIC CONCEPT.
Cutting of the Hands
1) I agree with "Muslimtruthrevealed" but I will not say that you are accusing the Quran lol
2) Many such prescriptions seem to have been neglected or interepreted literally by the Khulafa. What I want from you is evidence that Muhammad (or whatever his name was) prescribed literally cutting the hands of habitual thieves (and I am not asking for a verse or hadith, but a historic record outside of the Islamic "history" corpus). It is strange that non-Islamic documentation of the era mentions ludicrous festivals, kissing of the black stone, murdering of people in villages, praying in a certain direction, alliance with the Jew, and yet no cutting of any hands is mentioned.
Quran: Any kind of Authority
1) First off, I think Quran is a wee bit older than its alleged span of "revelation". Bro Ayman on the forums thinks that Muhammad was born at least 20 years earlier than the historic record, but I feel it may be half a century before that. This is my hypothesis which I intend to research (hopefully in this lifetime lol)
2) I do not think that "muslims/mu'mins" during the times of Muhammd were following a religion. They came from several religions who had come under one corporeal recognition, the majority being Arabs (who were predominently Hagaraeans along with jewish, christian, mandaean, perhaps even pagan sub-groups etc). Strikingly, this is in agreement with Robert Hoylad’s implied conclusion in Seeing Islam as Others Saw it.
3) Quran would have, at that point, served as a commentary for each group on their respective beliefs (and perhaps to seek freedom by being rational and abandon "muhaggar" their dogma - along with some prescriptions) and did not have the position of a "religious" scripture. But that would mean it did have "reminding" authority: Exactly what the Quran claims itself to be. Again, my hypothesis which I intend to research.
4) It is only later that we see this group morph into Muslims (Saracins or Ishmailites being their old nicknames).
5) Extra-Quranic or Para-Quranic revelations are not a new allegation. In fact sunni and shia circles have this belief prevelant. However there has been considerable debate over this on the forums so I'd rather you search and study those threads... or better yet, try to talk with Bro Ayman, Arnold Yasin or some of the other learned people on this forum.
Hopefully this gives you some understanding of where I stand.
PS: I have made some revisons to better explain my position...