be (at) home

Hi!

Are all these sentences correct English? Which ones are better?
He must be home before 10 o'clock / ...must be at home before...
...must be back at home before... /´...must be back home before...
...must be home at... / ... must be at home at...
...must be home until... / ...must be at home until

The only one which is wrong is

'must be home until.../... must be at home until' as this implies he has to stay at home until (up to a certain time). I think what you want to say is

must be home BY.../...must be at home BY...

Yes, exactly. Thanks
And the "at" doesn't make a real difference?

No, it doesn't. It seems to me
At home - BE
Home - AE.

Thanks!