1.We use you to talk about people in general including the speaker and the hearer:?
我們通常用you來談論人們，包括說話者和聽者：

You can buy this book anywhere > This book is on sale everywhere.

You can’t park here > Parking is not allowed here.

They don’t let you smoke in here > No smoking here.

2.We use they or them to talk about people in general:?
我們通常也用they或者them來談論人們：

They serve good food here.

Ask them for a cheaper ticket.

3.… especially about the government and the authorities:
特別是關于政府或者權威

They don’t let you smoke in here.

They are going to increase taxes.

They are building a new motorway.

They say it’s going to rain tomorrow.