To point out a few things:
Sabinus is a common Roman name. This official's title however, has nothing to do with Quirinius. To claim their titles are similar is frankly silly. He is described as a treasurer of Syria, so a financial official. That means he is likely a Quaestor, who were mostly delegated financial affairs. This is the lowest rung of the Cursus Honorum, the start of someone's career. What he is described as doing, securing Caesar's and Roman property in Josephus, is exactly what you would expect. Quaestors or military tribunes were often sent into client states, like Julius Caesar himself as a military tribune was sent to Nicomedes of Bithynia.
Quirinius however, is attested as a Proconsul of Cappadocia and Galatia and was a consul in 12 BC. His title is as a direct legate of Caesar in Josephus. He was far too senior for such a petty appointment. He was one of Augustus' most senior officials - in fact, appointed as Rector to Augustus' primary heir Gaius when he went east. He was basically his right-hand man, but also there to reign in the youth if he got out of hand. There is simply no way that Publius Sulpicius Quirinius, whose career was well attested and given a public funeral in Rome, would be securing Caesar's property in a petty client-state. That he would be appointed to incorporate one, sure, but to assume him the same as a unknown Sabinus is ludicrous. Tacitus would anyway have mentioned an adoption that such a change of name necessitates, as to Rome adoption was an honour bestowed on promising youths, bringing them into old families.
Further, Josephus' timing of the census fits Roman practice very well. A census was conducted when new provinces were incorporated, thus starting the taxation indiction for that province. That is what Quinctilius Varus was doing when Germania revolted, too. Numismatically, that is when Judaea appears as a Roman province. Censuses in client states are not well supported, and basically wasted effort. That is why the vast majority trust Josephus here - it fits Roman practice perfectly.
Josephus does have confused accounts sometimes, like Mucina and Paulina, but few doubt him here. As to the Judases of Galilee, why not? The accounts aren't as similar as the article posted in 107 claims. Read Josephus yourself. One is in Jerusalem and the Temple, another in Galilee around Sepphoris. Sepphoris was burnt archeaologically about 6 AD, so I see no reason to doubt it. Judas was a common enough name, as the NT attests. That a rebellion would try and gain the support of some Rabbi or Teacher or something is perfectly reasonable. That is what the Hasmonaeans always did, or what happened in 69 AD or 132 AD. A rebellion that did not try to gain the support of the religious establishment is unlikely to be worth noting at all. This reads to me as if someone claimed WWI and WWII had to be a reduplication of the same events because of all the similarities (belligerents, strategy of going via Belgium, etc.). We have limited sources here, and the claim of duplication is highly speculative - and less likely than actual two or three separate revolts in the view of the vast majority of scholars - with good reason. It explains Herod's actions at the end, his executing Antipater for instance; it explains Archelaus' deposition; it explains Sepphoris' destruction and the construction of Tiberias. That it requires a high priest to be deposed multiple times: So? High Priests were deposed multiple time. Hyrcanus II and Aristobolus were both deposed and reinstated many many times. It is really not implausible.
As to confusing Coponius and Quirinius - unlikely. The biblical Cyrenius was a common way Quirinius was transliterated at the time - remember, we aren't dealing witha petty official, but a major figure of Augustus' latter reign here. It would require more than confusing a rho for a p, but signifantly more letters. Further, Josephus was ignorant of Latin, and employed Greek scribes. Such a mistake is highly unlikely from any first century writer, and if anyone were to make it, I think Luke doing so more likely than Josephus whose sitting at the heart of Roman power, a client of Vespasian no less.