What is the proper word order here?

[Happy Puppy]

I would like to ask someone who is sure:

Do you know, what you are doing?
Does he know, what he is doing?

OR

Do you know, what are you doing?
Does he know, what is he doing?

[Tdol]

Do you know what you are doing?
Does he know what he is doing?

[Happy Puppy]

Thanks for the answer. :)

[Tdol]

You're welcome.

[Happy Puppy]

Another question:

Which one is better of the sentences below?

There is many of us.
OR
There are many of us.

[Tdol]

There are- plural, like 'many' and 'us'.