Hello everyone, it's very nice to know this place where I can clear my queries about English at last

This is my question:
I am always confused about Relative clause, make it short, the following are examples:

He is one of my friends who likes shopping very much.

London is the capital of England where you can see attractions such as Big ben.

The restaurant in this street which used to be my favourite is going to close tomorrow.


So my question is, is it correct to use relative clause like these? Are the relative pronouns referring the words in red correctly? Does it mean relative pronoun could be quite flexible to refer to any words preceding the relative pronoun?

Many thanks.