Okay, I can accept a time machine, and a super-intelligent Time Lord with plot-constrained inability to apply his skills and equipment to apply a simple non-dramatic solution to any problem. I can accept the concept of “life energy” and separation of mind and body. All of this just requires suspension of disbelief.
What I can’t cope with is the fact that in a show that features application of intelligence to solve problems, none of the laws of physics are stable enough to reliably engineer anything.
Why can “dead” people wander around performing work with no energy input?
Why do alien devices never need batteries?
And most importantly, why does no one ever dispose of an “invulnerable” Dalek by:
Hitting it with a shaped charge and letting the shockwave turn the sentient slime into squished jelly inside the perfect undamaged casing.
Blasting the perfect undamaged casing up, down, sidewise, into orbit or somewhere else where it can’t do any harm.
Pouring enough energy into the case or surrounds until the ambient temperature cooks the Dalek into roast squid?
Applying enough visible light wavelength energy to the Dalek that they have to either shield themselves into blindness or fry their sensors.
Doctor Who is about the melodrama, the jokes, the spooky bits, the running – lots and lots and lots of running – and the warm feeling that comes from hearing the Tardis making the same creaky, grinding noises it did 47 years ago. It is not about the physics, and never has been.
That said, Daleks are not merely shielded by their Dalekenium shells, but by an energy field as well, so who’s to say whatever energy you projected at them couldn’t be absorbed, deflected, or reflected back at you?
Also, what works against a Dalek once may not work against a Dalek the next time. They are an intelligent race, capable of adapting. This was explicitly demonstrated in the season 1 finale, in which Jack Harkness mentions Daleks, long-established vulnerability to bastic bullets. But when the humans actually fire on the Daleks, the bullets merely vanish in the protective force field. Also see the season 4 finale, in which Wilf tries to disable a Dalek by the age-old trick of obstructing its single viewing lens with a foreign substance: “My vision is NOT impaired! Exterminate!”
Of course some weapons do (or did) work against Daleks: The weapon the Doctor picks up (but doesn’t use) and the one Jack jerry-rigs in season 2, and the one’s carried by visitors from Pete’s World in season 4.
This is complicated by the fact that the Dalek’s chief enemy, the Doctor, refuses to carry or use an offensive weapon on most occasions.
I think he’s referring to Owen in the second season of Torchwood.
How the dead walk? Alien energy fields.
In any case, if physics is important to you, read a textbook. Don’t bother watching any science fiction – it’s is not and never has been about science, and Doctor Who/Torchwood are unashamed of that.