1.楼主前两个问句都是选择疑问句,不是一般疑问句.
所以其回答没有所谓的肯定或否定的区别,只需要挑选其中一个选项作答即可.
如：
1）Would you rather stay here or go home?你愿意呆在这里,还是回家?
答：I'd rather stay here./ Stay here.
2) Which would you rather have,apples or bananas?你喜欢吃苹果还是香蕉?
答：I'd rather have apples./ Apples,please.
2.第三个问句才是一般疑问句,肯定/否定回答如下：
Would you rather read a novel than read a poem?你宁愿看小说而不愿朗读诗歌吗?
肯定回答：Yes,I would.
否定回答：No,I wouldn't.
3.当然,在口语中的回答完全没有必要像上述回答那么死板,可以用一些符合句意及常用的口语来回答,如：I've no idea.等.