"If I understand this correctly, Mars lacks a magnetosphre to protect it from Coronal Mass Ejections, which occur, I don't know, in bursts every 22 or 44 years or so."
I believe the sun has a 11 year cycle.

"The result is that everyting on Mars will get fried, so tera-forming Mars is out of the question. Since terra-formning is out, not enough could be put into shelters to make it worth establishing a colony there. Finally, without any "there" there it becomes cheaper to do whatever exploration you wish to do with robots on Mars."

Terraforming is not necessary for colonizing Mars. Lowering the launch cost from Earth is.

"And if that news isn't depressing enough, everyone seems to think that I am just going to be the punching bag for their frustrations and take it with a smile on my face and continue to keep my good nature - "

Oh, must have missed the good nature.
:)

"Of course, I could vent my anger into an attack on manned Mars flight ever - it's not a position that I want to take, but I can take it, and enjoy considerable success with it, for that matter - "

The main problem with radiation is traveling to and back from Mars.
There are a number of solutions to this problem, but as I said the main problem is the cost of getting payload off Earth.