ElectriductD-2 Rubber Duct Cord Cover - 5 Feet Black Floor Cable Protector,D-2-5-BK

Do you need double sided tape for this D-2 Rubber Duct Cord Cover or wil it just lay flat on it's own?

I see that the center conduit is split for easy use, but how do I use the other channels? Must the chords be threaded?

Instead of buying the 5 ft. one, wouldn't this 10 ft. be better and cut as needed, as i don't know exactly at the moment how long i may need?

Is it rigid or does it come coiled up?