Wooden flooring.

I would be inclined to screw battens down on the concrete and secret nail the wood down (assuming it is T&G).

answer

yes, you can, but its really not advised.

it doesnt. Also expect cupping, which ruins the finish, and in some cases condensation and rot.

much better option. It is essential to leave enough gap round the edges though, failure to leave sufficient gap can cause structural damage.

the oak will all need to be glued to its neighbouring oak strips if you do a floating floor. And clamped together while it dries.

never heard of such a thing, and cant think of any reason to want it either.

The 3rd option is to put 2x2 battens down and screw the oak to those. A floating floor is much better though, as it has the advantages of crack resistance, additional soundproofing, and doesnt add as much height as screwing to 2x2s.

NT

You can glue it using the correct glu. I've just seen a builder do it (someone I trust who builds hi spec homes). He used the correct glue (black stuff applied with a notched spreader) and left the expansion gap. He also used a wood glue for the tongue and grove. For those interested he bought the wood from ebay at £22/m2, beech effect. It looks great and I'll be buying some for my house. Neil