2) it's correct but u d better add the verb 听 like this：
8) it's correct but weird...丽丽比查理喜欢考试 means both of them love exam but 丽丽 loves more. In other words, 查理 loves exam too. I think nobody loves exam... So 丽丽的朋友都觉得她很奇怪 but 查理 is also a 奇怪的人.
比 is very simple to make sentences. for example, 他比我高、他跑得比我快、他比我帅 etc.