Remember J.C. O'Neill's dictum, "Paul wrote some of all, but not all of any." His study of epistles of the era showed that those documents attributed to Paul were often much longer than other epistles. Very many scholars have seen interpolations in Paul's letters. The current understanding of 2 Cor is that it is a composite work that scholars attribute wholesale to Paul, but he was not responsible for the compilation of the parts.
When we come to the reference to Aretas in 2 Cor, we know that Aretas IV never held Damascus. It was a Roman protected city, a member of the Decapolis, and Nabataea was not part of the Roman empire until it was annexed under Trajan. It was in fact an enemy of Rome, which Tiberius would have crushed had he not died following the conflict between Antipas and Aretas IV. And remember that 2 Cor 11:32 talks of the ethnarch of king Aretas, ethnarch of what in Damascus? He is a figure representing Aretas, his ethnarch, so he is a high functionary of the king. The only reasonable reading is that he was the ethnarch of Damascus, Aretas's ethnarch.
I can accept that, except "the etnarch of Damascus".
So we can scratch Aretas IV as a non-starter as he never had his claws in Damascus.
Sure, but Paul never wrote Aretas IV was master of Damascus. And his etnarch in this city did not have to be the one governing it on behalf of Aretas IV. As I explained here: http://historical-jesus.info/61.html
The first person certainly aware of the fire-related persecutions of the Christians under Nero was Sulpicius Severus. The relationship between the report now in Tacitus Ann. 15.44 and that of Severus is not clear. I have argued that that in Tacitus was based on Severus, for Severus lacks the christological nugget. As to the strange little reference in Suetonius' life of Nero, the mention of Christians there is exceptionally strange, tacked on to a list of provisions to keep public order in the streets, which included banning pantomimes, public food stalls, chariot races and executing christians.
Well, I am far to be convinced about your arguments against the testimonies of Tacitus & Suetonius.
Suetonius probably did not have a high opinion on Christians, considering them as garbage, about the same as Tacitus did.
Eusebius reported there were many accounts of Nero's persecution of Christians:
History of the Church, II, XXV
When the government of Nero was now firmly established, he began to plunge into unholy pursuits, and armed himself even against the religion of the God of the universe.
2. To describe the greatness of his depravity does not lie within the plan of the present work. As there are many indeed that have recorded his history in most accurate narratives, every one may at his pleasure learn from them the coarseness of the man’s extraordinary madness, under the influence of which, after he had accomplished the destruction of so many myriads without any reason, he ran into such blood-guiltiness that he did not spare even his nearest relatives and dearest friends, but destroyed his mother and his brothers and his wife, with very many others of his own family
as he would private and public enemies, with various kinds of deaths.
3. But with all these things this particular in the catalogue of his crimes was still wanting, that he was the first of the emperors who showed himself an enemy of the divine religion.
4. The Roman Tertullian is likewise a witness of this. He writes as follows: “Examine your records. There you will find that Nero was the first that persecuted this doctrine, particularly then when after subduing all the east, he exercised his cruelty against all at Rome. We glory in having such a man the leader in our punishment. For whoever knows him can understand that nothing was condemned by Nero unless it was something of great excellence
OK, Eusebius was loosely quoting from Tertullian's Apology V:
Consult your histories; you will there find that Nero was the first who assailed with the imperial sword the Christian sect, making profess then especially at Rome. But we glory in having our condemnation hallowed by the hostility of such a wretch. For any one who knows him, can understand that not except as being of singular excellence did anything bring on it Nero's condemnation.