Could you please/would you please

Could you please 是can you please 更为礼貌、委婉的说法，并不是过去式，是“能否麻烦你……”、“请你……”的意思，更侧重“能否”及客观情况；回答时要注意，eg：A:“Could you please open the window?”肯定回答 B:“Of course”；否定回答：B:“Sorry, I can't open it because the windows are locked on the train.”
而Would you please 含有说话者一定的希望，期待对方愿意做某事的意味，“请你……”，更侧重“愿否”及主观能动；回答时要注意，eg：A:“Would you please open the window?”肯定回答：B:“OK”；否定回答：“I'm sorry, but don't you feel it is a little bit too cold outside?”
尽管两者有小小差异，但是在日常口语中，似乎两者经常通用，并没有区分得那么明显。

Could更加表示“能否...”
Would更加表示“愿不愿意...”
口语中，这两者区别不大，可以互用！

Would you please 更礼貌一点

差不多。都比CAN YOU 。。。。显得有礼貌。

没什么区别，都可以

一样。