Parent is probably suggesting that:

(a) what is "hate speech" is a vague term to be filled by whoever yields the power to define it (could be anything from talk against religion, to conservative worldviews, to class-war ideas, to racist beliefs, to complaints against politicians, and so on).

(b) what is a minority can also be vague and politically determined as opposed through raw numbers, and the power of a minority could be more than its size tells us (e.g. the 1% is a class-based minority, but most don't have an issue with going against them. Similarly, in certain cases it's one or more minorities that have the power against the majority - e.g. the fewer white-spanish descendants over indians and mulatos in some Latin American countries, or the white 20% against the blacks 80% in appartheid South Africa).

So, no, it's not clear cut that it's "in a society's interest to limit hate speech against minorities".

Hate speech is when you promote violence or persecution in some other way against any of the groups you mentioned. I am not sure what point A has to do with what hate speech is.

I believe you are conflating the definition of minority in this context. It means a disenfranchised portion of the population.

Incorrect. You're discussing censoring people with a different opinion than you, but using minorities as political cover, which is morally dubious.

That is not what I am discussing. I am making a statement about how to design a stable society with humane values. From the perspective of the society. Instead you went to make judgements about my personal beliefs.