1) Take a flashlight
2) Put a finger over the bulb and turn it on
3) Observe the surprising amount of light that passes through your finger.
The difference as far as health concerns is X-rays cause DNA damage, RF will simply increase temperature.
Increase temperature enough and you cause tissue damage of course, but we are talking milliwatts at the transmitter point source that falls off at inverse square, again similar to the amount of heating you would get from a low power LED held near your skin, actually less since as you pointed out RF mainly passes right through us rather than being absorbed.
This stuff should continue to be studied, but so should the effects of much higher power light bulbs just in case there is some damaging mechanism yet to be discovered beyond heating your flesh.
Actually, Google "microwave meat sparking" and you'll find plenty of videos --- but in almost all the cases, the meat is cut in a very specific shape (with sharp edges) that makes it concentrate the RF, and of course being a microwave oven the power density is very high. A human body is, to a rough approximation, a bag of water. It will heat, mostly evenly, when exposed to RF (some parts like the eyes do not have good cooling, hence are more dangerous to irradiate, but this is still a conversation about power levels many orders of magnitude higher than a phone would produce.)
Yes they are: https://en.wikipedia.org/wiki/Microwave_transmission
> The frequency has a very specific interaction with water.
No it doesn't: http://wtamu.edu/~cbaird/sq/2014/10/15/why-are-the-microwave...
Yes, I'll give you that
> in the microwave range
No. Water's first resonance is around 1THz, in the far infrared.
> which is why tabletop microwaves use that range.
No, they use 2.4GHz because that is what the FCC lets them use. The first microwave oven used 1GHz (https://www.google.com/patents/US2480679), later increased to 3GHz (https://www.google.com/patents/US2495429). Anything in that range will work.
In the end it is an uninteresting point however because it is an argument over what word to use, not fundamental differences in nature. The point I was making earlier which was misinterpreted was that microwave interacts with matter in a fundamentally different way than lower frequency RF, which is critically important to the topic of TFA. Microwaves excite dipoles on the atomic and bio-molecular scale. Lower frequency RF requires some sort of conductive material (or A LOT of energy) to form an antenna, on the other hand, which is why we are transparent to "RF" but not "microwave" (and hence, why some fields treat them separately).