as for the title "Do's and Don't's for composers"
"composers" definitly not equals "作曲家"
嘛,that's why I feel so unwell after I,have read your traslation.
it's looks like a very good guide for "not smart enough" young people,
but if you consider it "something a musician trying to educate another musician"
it's better like a taunt just like:
"well I can do these A-Z very well but can you do it as good as me?"
so "composers" here, better say "作曲的人、作曲者" or somthing else,
to avoid such a misunderstanding.