Dear HH
I am not replying to your other opinions because it looks like we are interpreting each other's replies in a totally different manner and this can go on for ever. But just for two things I would like to reply
To answere this, you might need to delve a bit into that 'who' were considered 'brahmins' in different time periods; and what were the acceptable practices in each time period for each region or tribal groups.
I think the scriptures are very clear as to who a "brahmin" is. Different brahmins did different things in various parts of India or abroad like smoking beedi, eating fish or meat or drinking liquor but does not mean they were authorized by the scriptures. Before I give quotes as to who a brahmin is, lemme give below what the Padma Purana says about the condition of brahmins in kali yuga. This gives a fair idea of what a brahmin is supposed to do or not. I don't know Sanskrit but giving it for authenticity. Below it is the English meaning.
brahmanah ksatriya vaisah sudrah papa-parayanah
nijacara-vihinas ca bhavisyanti kalau yuge
vipra veda-vihinas ca pratigraha-parayanah
atyanta-kaminah krura bhavisyanti kalau yuge
veda-nindakaras caiva dyutacaurya karas tatha
vidhava-sanga-lubdhas ca bhavisanti kalau dvijah
vrtty-artham brahmanah kecit mahakapata-dharminah
raktambara bhavisyanti jatilah smasrudharinah
kalau yuge bhavisanti brahmanah sudra-dharmina
In Kali-yuga, all four varnas are devoid of character and proper behavior and are addicted to sin. The brahmanas are devoid of Vedic knowledge and sacrifice. Giving up the five sacrifices recommended in the Vedas and all brahminical behavior and consciousness, they engage in inferior activities. They collect charity to satisfy their unlimited appetite for sense enjoyment. The brahmanas of Kali-yuga are characterized by the qualities of lust and cruelty. Unholy in deed and thought, they take pleasure in envy and malice. These professional thieves blaspheme the Vedas, drink liquor, and exploit women for sex,
taking great pleasure in adultery and fornication. They accept extremely sinful means of maintaining their lives and, posing as swamis, dress in red cloth and wear long hair and beards. In this way the wretched so called brahmanas of Kali-yuga accept the dharma of sudras, that is, they become fourth-class men.
If you see further into our scriptures there is absolute clarity but we human beings have interpreted them the way we like and acquired characteristics which we later justify.
sudre caitad-bhavel-laksma dvije tac ca na vidyate
na vai sudro bhavec-chudro brahmano na ca brahmanoh
If it is seen that a sudra has the characteristics of a brahmana he should be considered a brahmana. Similarly, if a brahmana has the characteristics of a sudra he should be considered a sudra. (Mahabharata, Vana Purva 180.25)
yasya yal laksanam proktam pumso varnabhivyanjakam
yad anyatrapi drsyeta tat tenaiva vinirdiset
If one shows the symptoms of being a brahmana, ksatriya, vaisya, or sudra, as described above, even if he has appeared in a different caste, he should be accepted according to those symptoms of classification. (Bhag. 7.11.35)
etan me samsayam deva vada bhutapate'nagha
trayo varnah prakrtyeha katham brahmanyamapnuyuh
sthito brahmana-dharmena brahmanyam-upajivati
ksatriyo vatha vaisyo va brahma-bhuyam sa gacchati
[Uma said] "O Siva, master of the bhutas. O sinless one, through what
kind of personal characteristics can the three classes of men ksatriya, vaisya, and sudra become brahmanas? Is it possible for them to become brahmanas? Please enlighten my doubts on this subject." Siva said, "If a ksatriya or vaisya is established in brahminical behavior, and spends his whole life in brahminical conduct, it is seen that such a person has attained brahminical status.
(Mahabharata, Anusasana Parva 14.3.5,8)
The above clearly shows that there were fixed rules as to conduct of the four varna classes and they did not differ with region or time period. Clearly we human beings have adopted different things as per our convenience which has been passed on to generations.
Since you asked about the evidence of kasappu kadai the one which readily comes to my mind is a episode of Enge Brahmanan. I don't remember the names of the characters involved but the story goes like this roughly. An ordinary man does great tapas to acquire powers and when a bird tries to disturb him he opens his eyes and the bird is reduced to ashes. Happy that he has acquired the powers and a bit arrogant he goes for alms and knocks the door of a house. The house lady opens but makes him wait as she is serving her husband. After some time she comes to serve our man who gets angry and pronounces a curse. The curse has no effect and the lady asks, "What, you thought that I am like the bird you reduced to ashes". The man, astonished asks her how she knew and she says since I serve my husband dutifully I have acquired this power. The man wants her to teach him but she says go to this butcher who will teach you. The humbled man goes to the butcher who asks if the lady sent him. The tapaswi is further astonished and asks him how a guy who is killing animals knew about this, the butcher says butchering is his job which he should perform but he serves his parents truthfully so has acquired this power. The story goes further but am quoting just to show that a profession called butchering did exist. Even the names of the characters were mentioned but I can't remember them.