1) The trouble is, the Emperors of the period, Constans II and Constantine IV, were both relatively competent individuals, overwhelmed by wars on multiple fronts and religious chaos. Barring a case of insanity, I can't really see either of them majorly screwing things up to the degree you wish, so I think you're going to have to attempt to overthrow one of them. Perhaps have Constans II killed at the Battle of the Masts and then have the Empire dissolve into chaos.
2) And I'm not especially bothered about the fall of the ERE, it's more, as a Christian, this TL will see my own faith wiped out, which upsets me slightly. I'm sure I'll get over it. Will Rhomanian Islam have several links back to Christianity? Since this is very early Islam, and much is able to be changed... perhaps Jesus could be a prophet equal in stature to Mohammed, and Muslims would celebrate the birth of the Prophet Jesus Christ every year? Up to you. Hope this helps
1) Well, if that could eventually result in soldification of Arab control over Anatolia, the precondition I'm looking for before the Constantinople assault. Also, I need to find a way to exploit existing schisms so things will be easier for the Arabs in Anatolia. Was Constans II in some problem reconciling a doctrine with another ?
2) Very early Islam wasn't really that vague of an Islam, actually. If anything the Islamified Greeks will be as Christian as Islamified Persians are Zoroastrian, or at best as the post-Ridda war Bedouins are Pagans. Since Jesus possesses a pretty positive image among muslims, he will remain be respected, but only up to the limit of Islamic ethics. In fact I want this muslim greeks to be as Islamic as the OTL Greeks have been as Orthodox Christians. Not to mention that I want to throw schism between Christian doctrins into the mix of the potion to catalyze the Greeks eventual decisive mass conversion to Islam. In fact, ITTL dummies in history will know them best about their history with the Arabs as people who got involved into conflicts with the Arabs about whose Islam is the purest !
The Greeks will be fairly Arabized of course, but will maybe lesser then the OTL Persians, depends on how much of an Arabization they will really need ITTL. They will be holding firmly to anything that is "Islam and Rhomanian" to the point that they will be quite used to regard both things as basically equal to each other, and will be critical about heterodox movements that will emerge ITTL surface of the uncivilized Arabian deserts.
Those being said, doesn't mean the Christian Greeks will be wiped out but of course they will be politically impotent. But that is mostly why they will survive ITTL.
And also, doesn't mean I reject your proposal of a version of Islam as utterly impossible. It's just that I don't really consider the Greeks as really that isolated and hard-headed for that. Ultimately, while this TL will be quite great of a Christian anti-wank, doesn't mean TTL Christians won't be having their interesting moments of glory and grace and some entirely new breeding grounds for the faith, that most people just won't expect it will be them
1) Sadly, the Battle of Phoenix-as-PoD kind of ruins an interesting rebellion waiting to happen, that of Theodoros Rshtuni. Get him and Mu'awiyah some more success in the 652 Armenian campaign (preferably by killing off Konstas, who is personally leading the Thraikian army) and there's probably enough momentum in there to get a revolt of somewhat equivalent caliber to that of Thomas Slavos. Something like that would allow the Arabs to irrupt through the Taurus/Antitaurus frontier, which will be a nice launching pad to Konstantinoupolis a decade later.
2) And that means Yennadios can have his independent African Exarchate (have Nikephoros Patrikios rescue a portion of the field army after the fall of the capital and join him for even longer-lived North African hijinks; this is before Qayrawan has been founded, so the fall of the Exarchate isn't yet preordained), possibly with extra Italy and Sicily. Yeah, it's got way too many butterflies, but it'd be kind of cool.
1) Hmm....
Sounds like nice idea. Can you explain further about this ?
2) Hmmmm......
Will this be a potential thorn for the later muslims when they set up their eyes for Italy ? Because I have some plans for Italy....
Hasn't it already agreed upon that any nature-based PoD belongs only to ASB section ? If no, than Peshawar Lancers can't be an ASBTL for its "The Fall"....