We may not have to use immense amount of thrust/ energy to accomplish warp drive. Like nature itself, space gives everything needed to do things for us. It's just a matter of discovery and experimentation. Such as the use of black holes, and star gates that have been seen opening and closing above storms on our very planet. However, my friend, I must correct one statement. Subspace, DOES exist and beings buildings, vehicles could be within a distance of only one atom away. It is postulated that the 4th dimension and subsequent 5th through 11th dimensions are all variants of so called subspace.