Does ducted fan require more engine torque than unducted-fan,at same RPM?
Two identical fans […]
I think ducted fan require more torque for same RPM

Yes, a little more. The shroud prevents the air flowing directly around the tips, allowing them to produce more thrust. And this extra thrust comes with induced power.

but in theory wall to wall airfoil must has lower drag than 3D wing at same speed and same AoA.

No, it doesn't. The comparison is always made for the same lift, never the same AoA.
For the same AoA the drag should be higher for the same reason as above.