Are there caste equivalent attitudes towards Arabs, Euros, East Asians and so on? Or from a different angle, Muslims, Christians, irreligious, etc.
Or does the framework not apply to those outside of the Hindu community?
The question you need to ask yourself is "Does this person come from a background that makes sense to my own principles?"
So the answer to the question depends both on the person asking the question and he subject of that question.
Note: You also need to differentiate between "external" world and "private affairs". Most castes in India dont give much shit about caste when it comes to doing business, hiring, casual friendship, offering/accepting services etc. but care about it deeply when it comes to sharing food/getting married/dating/renting private spaces etc.
In Indian history, certain groups/clans/families were associated with certain jobs. How close those jobs were to the throne or to the Mandir determined your 'rank'.
Fun fact, this is why the last name Singh exists, as a rejection of that system.
That's not to say this interfaith caste constructs don't exist, but I've never heard an in-person mention of them in all my life. I'm genuinely curious how widespread they actually are. Were they something that had more weight back in the 16th century, maybe? Conversely, I have heard Indian friends discuss caste discrimination in places like Microsoft.
https://www.thehindu.com/opinion/op-ed/reaching-out-to-pasma...
https://frontline.thehindu.com/books/caste-amp-muslims/artic...
https://www.thehindu.com/opinion/op-ed/a-picture-of-islam-th...
Despite its name, the newspaper I have linked to has long been a left and liberal leaning one and is a bullwark against the current right-wing government and temperament spreading through the country.
It should be obvious that the above is merely a historical note nowadays and is no longer valid.
AFAIK, it did not. It came about from the Buddha's teachings, which were not about caste, but about suffering and its cessation via attaining nirvana (but I am not an expert on Buddhism; we only learned some about it in school).
My guess is that, instead, later, many people may have converted to it, maybe some due to orthodoxy.
I am talking about olden times. In recent times, neo-Buddhists definitely may have converted due to the caste system. I have read something about that earlier. See Dr. Ambedkar.
Your above point itself proves what I said: "dueling literature"! Heh.
Groups like the Veerashaivas were concertedly anti-caste discrimination but the Buddhists were decidedly not. They’d be more like a Kshatriya revolt against Brahmins but that’s just upper-caste infighting, not anti-caste. Similarly with Muslim and Christian converts, the first ones were predominantly, if not almost entirely, Brahmin.
This is a modern myth, that has been proven to be grossly untrue, time and again.
Buddhism was a mostly upper caste phenomenon.