At this point it is like a god. No one can prove that he exists and no one can prove that he doesn't exist. We once logically assumed that the universe was created by a god. Any other cause was more complex with the information we had. Nowadays we know more. Much more.
In the same way we should assume now that there is no subspace. That doesn't mean that we should hold to this assumption when experiments indicate that there is a subspace.
That's probably going to be the biggest assumption I am going to do today.
How do you rehabilitate someone who gets great pleasure in (effectively) torturing innocent people?
You offer them a job at the FBI.
That said, I doubt its only 10% loss...
According to the WiTricity FAQ the efficiency can be quite high:
Q: How efficient is WiTricity technology?
A: The power transfer efficiency of a WiTricity solution depends on the relative sizes of the power source and capture devices, and on the distance between the devices. Maximum efficiency is achieved when the devices are relatively close to one another, and can exceed 95%.
What "relatively close to one another" means, how big the marketing sauce on that is and if it still works with other conducting items with 1 km radius remains to be seen.
My own limited knowledge of this stuff tells me this could work. High frequency usually helps with transmission efficiency and resonant coils help a lot too.
The WiTricity site mentions near field transmission. I can't find the exact frequency, but I'll assume that it's the same as their phone charger frequency (which is in their white paper): 6.78 MHz. The wavelength in meters for that is 300,000,000/6,780,000,000= 44 meter. The near field is up to about a wavelength in distance, so the near field for this should be up to 44 meter. I have not enough experience to say much insightful about the efficiency drop off inside those 44m.
A black hole (size 0) combines with another black hole (size 0) to form a bigger black hole (size 0). 0+0=0 so that works.
As for location: black holes do have a location. It's at the center of their schwarschild radius.
All this is difficult to know for sure. We can hardly go and take a look.
That does leave us with some loopholes.
1. Our understanding of physics could be incomplete. There is much yet to discover, so this may be the case. However, the current models are verified extremely precisely.
2. Warp drives. Not traveling through space-time but morphing it would help. However this seems to require massive amounts of energy. I believe the last calculations said: about the mass of Jupiter.
3. Subspace. Not traveling through space-time but through something else would help. However we have no reason to believe there is a realm outside space-time, let alone get there, let alone survive there.