This is your big night.

今儿晚上可是你的好日子。

It's been great talking to you.

和你谈得真高兴。

You'll send yourself to an early grave.

你这样会未老先衰的。

Do you get the message?

明白我的意思没有？

What does that mean in plain English?

你能不能用大白话解释一下？

I must take issue with your over what you said at the meeting.

我要和你好好谈谈你在会上说的那些话。（take issue with someone: 对某人的观点提出异议。）