Casual vs Cavalier vs Nonchalant vs Indifferent

Question

I'm having a hard time deciding if casual, cavalier, nonchalant and indifferent could be used interchangeably in such contexts as the following:They (except the last one) are examples cited in Merriam Webster's either Unabridged Dictionary or Citations.

Cavalier

He has a cavalier disregard for the rights of others.

People are cavalier with facts, let alone with opinions.P. 9 JOURNALISM MADE SIMPLE David Wainwright W. H. Allen, London 072 W13j 1972

Nonchalant

She faced the crowd with the nonchalant ease of an experienced speaker.

The team may have been somewhat nonchalant at the beginning of the season, but they now know that they need to work hard.

Casual

were casual with their hogs and let them run through the peanut fields after harvest. P. 62 Roon Frost GOURMET Vol. XLI No. 4 April, 1981

Indifferent

How to remain indifferent to one's pleas both in times of trouble and in times of joy.

Answer 1

Cavalier involves a lack of concern for someone or for some principle.

Nonchalant involves an apparent lack concern for some difficulty or risk.

Casual involves a lack of concern for formality or regulation or order or rule.

Indifferent involves an utter lack of concern or total uninvolvement.

Answer 2

It would seem to me that they are all variations on the concept of general indifference.

Cavalier indicates a spiteful or mocking indifference.

Nonchalant suggests a subtle attitude of indifference to avoid drawing notice or to appear unimpressed.

Casual would be a relaxed indifference or an unwillingness to exert effort beyond necessary