麦霸，你好。你列举的成语都是非常常用的，在日常对话中使用并不奇怪。“络绎不绝”和“恨之入骨”可能较书面一些。一般说“人很多”和“恨死了”就行了。我在对话里就经常用成语，虽然我周围的伙伴们不是太常用成语。有时我说的成语我家人还听不懂。囧。

- 寸步不离- 浑/混水摸鱼 - 胡说八道- 水土不服- 人山人海- 恨之入骨- 络绎不绝 在我看来，这些词大部分都不是成语，是很平常的四字词组罢了，所以口语中也很常见（现实生活中的口语用的少些，电视剧的人物中的口语会很常见）。现在的汉语成语词典，恨不得只要是四个字就当成成语收录，我觉得这样做不对，能称的上成语的比如：对牛弹琴，叶公好龙，唇亡齿寒等等，它们都有自己的出处，有的是历史上的典故，有的是名人名言名诗等等经过精炼而成，这才能算作成语。有些完全是四字的简单组合，就是字面上的意思，也没什么出处，所以根本不算作成语，有许多只是老百姓的口头用语，所以应该叫俗语。真正的口语，口语中用的肯定不多，当然有些知识分子之间的交谈中成语会用的多一些。

some are used in conversations and some are always used in articles

I dont use 人山人海 in normal conversations, I would say: 人超多，那里人巨多，那里人多到想死哦

Yes, I would say 寸步不离 or 胡说八道 or 水土不服 or 人山人海 in my daily life. Usually idiom all have a short story in Chinese (not every but large proportion), for example 兵不厭詐、愚公移山、東施效顰、朝三暮四、朱門酒肉 etc. Therefore you also can say we prefer to use a short sentence or word to describe the same situation what you are when you are talking with someone. We learned idiom from TV show or movie or school etc when we was still Childhood. So maybe some low level of education person are not often SAY idiom in their life, but they still can understand the idiom, cause it was filled with Chinese daily life. Hope it can help you