The basic answer to your questions is 尋, when used on its own, usually only appears in (very) formal written Chinese, works of literature and poetry. There is a famous poem by 李清照 that starts "尋尋覓覓，冷冷清清，淒淒慘慘戚戚". Here, 尋 means 找, it's just a more formal and literary way of expressing the same thing, looking or seeking. If you want to say look for something, then 找 usually does the job in spoken Chinese. 我在找我的手機 I'm looking for my phone 你找到了沒有？Have you found (it) yet? In written Chinese, you can change this to 尋找 我在尋找一份新的工作 警方正在尋找罪犯的蛛絲馬跡 The police are looking for traces of the criminal As for your second question, read this article: https://resources.allsetlearning.com/chinese/grammar/Comparing_%22youdian%22_and_%22yidian%22 Laurence

寻 （寻） xún 找，搜求：寻找。寻觅。寻机。寻问。寻访。寻衅。追寻。寻章摘句。 古代的长度单位（一寻等于八尺）：寻常（古代八尺为“寻”，倍寻为“常”，都是平常的长度，后泛指平常、素常）。 觅找 找 zhǎo 寻求，想要得到：寻找。找人。找物。 退回，补足：找钱。找平。找齐。 觅寻 “一点儿”:1.表示不确定的数量:我没活做了，你分给我一点儿吧/2.表示很小或很少:只有那么一点，够用吗？ “有点儿”：1.表示数量不大或程度不深：锅里还有点剩饭。2.副词，表示略微；稍微（多用于不如意的事情）：今天他有点儿不大高兴。 同时，“有点儿”可以做谓语，如例子；“一点儿”则不可以。“有点儿”可以称为“有一点儿”。

1)In modern Chinese "寻" is probably not a word anymore. When it combines with "找" into "寻找" it means "look for". However this word is rarely seen in a conversation because it sounds way too formal. "找" can be used independently as a word which means "look for" as well. You hear it much more often in a conversation since it sounds casual and natural. 2)There exists no difference because they are incomparable. One is a part of the phrase structure of the other. 有点 = 有 + 一点. For example, "move over here a bit"=“过来一点”. "the steak is a bit raw."="这牛排有点/有一点生". Good luck!

- 寻=Searching for and 找= Finding or looking for (something) - 一点 ( a bit) and 有点 ( a little)

When you are using it in front of an adjective，I believe you use 有点 not 一点. e.g 我有点胖 . I don't think you can say 我一点胖。 But check with a native speaker!