Hi!

I think that I've heard that if you heat something until it is a hard
unrecognizable crunchy lump then maybe that could be
true.

I believe that is correct, but you can burn food to that point with
any sort of cooking device. Burnt food is not good, but I don't know
that it will do much harm.

But for general reheating of food or beverages is there a
concern?

No. The FAQ for this group discusses it further.

I will never trust manufacturers who's agendas are purely financially
driven to tell me the truth

That's somewhat true, but one must consider the inverse: a company
that kills or injures all of its customers soon doesn't have any! And
those that do, whether intentionally or not, get found out at some
point.

and I still don't believe that irradiating oneself with a blue tooth
headset for hours on end or even using a cell phone for that
matter can ever be in the least bit healthful...Lenny

The last I knew, the effects of this were not fully understood
(although they have been researched). It has been shown that there is
some reaction (an excitation, if memory serves) of tissue in close
proximity to an active cellular telephone or similar device. What this
may or may not be doing at the same time is unclear.

I don't do the whole cell phone thing just because of the rudeness
factor--and the fact that it's little more than an electronic leash.

I know from having used a communications radio with an earphone that I
become really "weirded out" by not hearing ambient sounds clearly out
of one ear...so much so that I could not use the radio. So there's
that, and there's also my opinion that there isn't a Bluetooth earset
in the world that doesn't make one look like a dork.

William