1.此两句的主语的确不同.
第一个主语是this,而第二个主语是this book.
判断原则:将其还原成陈述句,并考虑中文的翻译.
Whose book is this?还原成陈述句为:This is whose book,所以其主语为this;
Whose is this book?还原成陈述句为:This book is whose,所以其主语为this book.
2.此句无法判断,要看说话人的具体含义,楼主无须细究.
1)如果是说“你的经理是谁?”,则主语为your manager.
还原成陈述句:My manager is Mr Zhang.
对Mr Zhang划线提问,即为:Who is your manager?
2)如果是说“谁是你的经理?”,则其主语为who.
还原成陈述句:Mr Zhang is my manager.
对Mr Zhang划线提问也是:Who is your manager?
3)不过,楼主对宾语从句句序的理解十分正确.
如果是:I don' care who your manager is,则从句主语为your manager;
如果是:I don' care who is your manager,则从句主语是who.
因为名词性从句(含宾语从句)的句序均为:引导词 + 陈述句(主谓等结构).