The technolgy of engineered explosive charges has an interesting exercise with getting the right amount of high density explosive distributed well enough to attain, "maximum containment" with a vessal that can fracture such as concrete. You would have to see above ground blasting in highly stratified terrain and compare blast that were centered in hard formations as to blasts not centered and closer to softer adjacent rock to know what well contained really means.
To the observer it means quieter, or muffled, it means really fine breakage, it means you see a relatively gentle heaving of materials rather than a blast of a gas jet leaking out. The delay systems took care of the rest and had a minimal amount of explosives detonating at any time.
It also means that I highly doubt you have much experience with explosives, beyond maybe seeing a few.
What you're discussing sound smore like the difference between cutting and cratering charges. Low-speed explosives are used to move objects, things like AN-AL, and the classic diesel fuel/fertilizer mix. Higher speed explosives (like the C-4 you mention) are cutting charges, with high explansion rates. The dispersion needed to have anything similar to a cratering effect with C-4 would be ridiculous. Of course, the same goes for cratering charges, but they aren't that much more plausible.
Also, your consistent display of ignorance regarding the capabilities and action of thermite shows your lack of knowledge in the area, as well.
Thermite does not "burn at a speed equal to many explosives". If it did, it would
be an explosive. But it isn't. It's an incendiary. It'll melt through an engine block, sure, but it takes a while (15 to 30 seconds). And it burns
down, so it is highly difficult to use it for cutting vertical columns. Not to mention it produces enormous amounts of iron and aluminum oxide slag, as well as residue of the ignition mixture used (of which no evidence was found). For that matter, no traces of explosive compunds or blast patterns was found, either.
By the way, your picture of "a steel cloumn cut by shear forces" is a complete fabrication. I'm calling you out as a liar. That was a column industrially cut, not a cut from blast. Again, this points out to me that you don't have much experience with explosives, except perhaps seeing a few go off from a far distance away.
I, on the other hand, am a combat engineer in the military, with several years of experience in demolitions, cratering/clearing, and EOD, including both electric and nonelectric detonations systems (mostly MDI), as well as improvised explosives and incendiaries. You, Christophera*, are a liar.
*-Is it just me, or does this sound like the name of a venereal disease?