"Willy nilly" is not what we are dealing with, but why would you ever doubt that some Jews could modify a pagan practice in the light of Scripture and history?
Then God turned, and gave them up to worship the host of heaven; as it is written in the book of the prophets, O ye house of Israel, have ye offered to me slain beasts and sacrifices by the space of forty years in the wilderness? (Acts 7:42)
Kabbalah its origins in pagan magic and mysticism: http://www.talmidi.co.il/htm/articles/articles58.htm
The problem with the second is that your source admits that Purgatory had developed by over half a century before Christ and a century prior to His Crucifixion. So the concept of Purgatory dates back to before the Apostles.
That is simply your problem not mine. That some Jews did what is not in Scripture after a surprisingly innovative period only testifies to spiritual declension, not orthodoxy.
What you desperately need but will never ever find is at least one example of someone on earth other than pagans praying to created beings in Heaven, and of them having the Divine ability and position to hear virtually infinite prayers addressed to them, which only God is shown having,
Now we are stuck with the final stumbling block Scripture. And we are back to the Sola Scripture vs Scripture, Tradition and Magisterium debate.
Meaning since you cannot find it in Scripture you need to channel it into doctrine from another source.
Concerning the passages of Talmud you cited, did you look up any commentaries written by Jews on them?
Do you really want to follow Jewish tradition and some of the nonsense in the Babylonian Talmud, at least from some of what i read?
--"There were two things which God first thought of creating on the eve of the Sabbath, which, however, were not created till after the Sabbath had closed. The first was fire, which Adam by divine suggestion drew forth by striking together two stones; and the second was the mule, produced by the crossing of two different animals." -- P'sachim, fol. 54, col 1.
--"The Rabbis have taught that there are three reasons why a person should not enter a ruin: 1. Because he may be suspected of evil intent; 2. Because the walls might tumble upon him; 3. And because of evil spirits that frequent such places." -- Berachoth, fol. 3, col 1.
--"The stone which Og, King of Bashan, meant to throw upon Israel is the subject of a tradition delivered on Sinai. 'The camp of Israel I see,' he said, 'extends three miles; I shall therefore go and root up a mountain three miles in extent and throw it upon them.'
So off he went, and finding such a mountain, raised it on his head, but the Holy One -- blessed be He! -- sent an army of ants against him, which so bored the mountain over his head that it slipped down upon his shoulders, from which he could not lift it, because his teeth, protruding, had riveted it upon him." -- Berachoth, fol. 54, col. 2.
--"Three things are said respecting the finger-nails: He who trims his nails and buries the parings is a pious man; he who burns these is a righteous man; but he who throws them away is a wicked man, for mischance might follow, should a female step over them." -- Moed Katan, fol. 18, col 1.
Gittin 69a. To heal his flesh a Jew should take dust that lies within the shadow of an outdoor toilet, mix it with honey and eat it.
Shabbath 41a. The law regulating the rule for how to urinate in a holy way is given.
Yebamoth 63a. States that Adam had sexual intercourse with all the animals in the Garden of Eden.
Yebamoth 63a. Declares that agriculture is the lowest of occupations.
Sanhedrin 55b. A Jew may marry a three year old girl (specifically, three years "and a day" old).
Sanhedrin 54b. A Jew may have sex with a child as long as the child is less than nine years old.
Kethuboth 11b. "When a grown-up man has intercourse with a little girl it is nothing."
Yebamoth 59b. A woman who had intercourse with a beast is eligible to marry a Jewish priest. A woman who has sex with a demon is also eligible to marry a Jewish priest.
Abodah Zarah 17a. States that there is not a whore in the world that Rabbi Eleazar has not had sex with.
Hagigah 27a. States that no rabbi can ever go to hell.
Baba Mezia 59b. A rabbi debates God and defeats Him. God admits the rabbi won the debate.
Gittin 70a. The Rabbis taught: "On coming from a privy (outdoor toilet) a man should not have sexual intercourse till he has waited long enough to walk half a mile, because the demon of the privy is with him for that time; if he does, his children will be epileptic." - http://www.catholicapologetics.info/apologetics/judaism/closer.htm
Just as partial list, and i cautiously presume they are legit despite the source,.
Shabbath 41a.
I shudder to think that the above I violated at least three times a day while deployed in the middle of a desert.