其实用kindly表示“请”，在现代英语中已不常见。

▲《柯林斯高级英语学习词典》第5版的解释是：Ifsomeone asks you to kindly do something, they are asking you in a way whichshows that they have authority over you, or that they are angry with you. （表示因有权让人做某事或对其恼怒）劳驾，请。

Will you kindly obey the instructions I amabout to give? 劳驾你服从我要给出的指令好不好？

▲《剑桥高级学习词典》的解释是：used when asking someone to do something, especially when you areannoyed with them but still want to be polite（尤指恼怒时尽量表示礼貌）请，劳驾。

You are kindly requested to leave thebuilding. 请你离开这座房子。

▲就你提出的四个句子，我个人认为，前面两句中的please也可以换成kindly（当然这样一换，语气上就有区别了）：

Would you kindly speak less quickly? 麻烦你讲慢一点好不好？

Would you kindly wait for me to get ready? 请你等等我，让我作好准备好不好?

但下面两句感觉不能换用kindly：

Hand in your examination papers now, please.现在请把考卷交上来。

I want it typed right away please. 请立刻把它打印出来。