This made me so very happy! Well done!

The majority of the dose at airline altitudes is from neutrons (55%), with only a small component from photons (gammas are photons) - 5%. This is, of course, on average. I do not think anywhere in the preprint they claim to be able to measure anything but photons. Therefore, a cell phone will not do a great job of monitoring your radiation dose at airline altitudes.

However, there is a tool being developed by NASA which does a real-time calculation of your radiation dose along an airline trajectory. Check out NAIRAS

References:
Cosmic Radiation @ skybrary
NAIRAS aircraft radiation model development, dose climatology, and initial validation

As AC said below - there is no funding to do this. In addition to no funding, there is no incentive. Speaking in generalized terms, scientists are judged on their research record. That is a combination of:
1. How much money they have brought in through grants.
2. How many papers they have published.
3. The prestige of the journals they have published in.
4. How many times their papers have been cited by other researchers.
So, if you keeping your job depends on those 4 things, where is the incentive to check the work of someone else? Especially large, difficult, and expensive experiments. At best, you get a quick "Comment on XYZ" paper that questions some findings and the authors reply with a "Reply to Comment on XYZ" telling you why your comment is rubbish and you didn't understand what they were saying.

This is nothing new. Paypal sucks when it comes to this stuff. If you still use it and this happens - you should have known better. Your own fault. Stop using them and maybe they will get the hint. Or maybe they will just go away.

While there certainly are some humanities students who get support - most of them do not receive full support from their institution. Typically, half time TA with no tuition coverage. This can also be the case for engineering PhDs at some institutions. Almost all science PhD students are typically guaranteed 2 years TA plus tuition even at the very smallest schools. In addition, non-STEM related PhDs take longer (about 1.5 years longer at the median). This leads to more student loan debt for non-STEM PhDs compared to STEM PhDs. Please see this study for a very nice comparison: The Price of a Science PhD

In addition, you make what I believe to be two assumptions by implication about Universities:
1. That professors are hired to teach.
2. That TAs will do a worse job teaching than professors.

Professors are NOT hired to teach - the exception is small private colleges without graduate programs. Professors are hired to bring research money into the University. The University takes in the region of 40-60% off the top of grants "for institutional research support." While this is not always the case (for some grants, the granting institution require the university to commit matching funds) it is more than the norm. Secondly, while professors are typically more knowledgeable in the subject and typically have more experience teaching (by virtue of spending the time as a TA during graduate school), that does not mean they are the better teachers. The best teachers I ever had were evenly split between professors and TAs. While not scientific, my colleagues experiences were similar.

No, I don't just mean Earth. All places outside the near vicinity of the sun, the storm is isotropic after initial onset. Also, it is all of them, not just low energy. As I have already explained it is the magnetic fields carried with the storm that causes this. However, SPE don't have the spectral hardness of GCR typically we only model them up to 1 GeV or so, but some events have had fluxes measured in the 10s of GeV energies.

It is isotropic - coming from every angle and direction. The spatial extent of the event is larger than the Earth and the particles rescatter many, many times off the magnetic fields carried with the storm. Those two factors create the isotropy. Sorry, after the initial shock, there is no directional dependence.

Your statement that you know the direction of solar cosmic rays is incorrect. The initial onset of a solar particle event maybe anisotropic, but soon after, the solar particle event is isotropic once it arrives. This is due to the internal magnetic field of the event that travels with the solar event.

Yes, the GCR does extend to those energies, however, the peak flux of GCR is at about 500 MeV. Which over a million times lower than LHC. This energy range is available all over the world.

Not quite. Cosmic rays are made up of mainly very energetic protons (compared to low energy alphas (helium nuclei) or betas (electrons)) which are very penetrating. For instance, the average range of a 500 MeV proton (near the peak in the cosmic ray spectrum) in aluminum (a common spacecraft pressure vehicle) is about 55 cm or almost 2 feet of aluminum. That is a huge amount of material to put into space.

So, you are correct, stopping low energy particles, especially light low energy particles doesn't take a lot of material. But when the particles are protons and at much higher energies, then it is no longer that case that thin layers of material will stop them.

For high energy alphas, for instance, you also have to account for the nuclear interactions with the shielding material. The cosmic ray nuclei will collide with target nuclei in the shield and create giant sprays of secondaries that are more penetrating than the original particle, increasing the radiation dose received behind shielding.

Active shielding (as opposed to passive shielding that uses more mass of materials) is not a new idea [1]. The Rutherford Appleton Group every other year or so contacts NASA saying, look what we can do. Annoyingly, they do the contacting of NASA through the State department occasionally... NASA looks at their design, says "Uh huh, have you done a tech. demo yet?"
RAL says, "Yes, here are the results."
NASA says, "Yes, but this is for 10 MeV electrons. Which are not really part of the space radiation problem. Where are the higher energy proton and heavy ion results?"
RAL says, "..."

Space radiation protection is fundamentally different from terrestrial radiation protection. Space radiation is much higher energy and consists mainly of protons (but also heavy ions are important due to the Z^2 effect of radiation dose). And it is omnipresent - you cannot get away from space radiation - it is everywhere.

See, the problem with the unconfined magnetic field work is that the size and mass of the equipment to make a magnetic dipole against cosmic rays is prohibitive. The most recent analysis that I know of is by Paluzek [2] and needs a million kg in equipment with a diameter of 100 meters...

A nice review of the science and engineering aspects of active shielding can be found in Townsend (2005) [1].

[1] Townsend, L.W., "Critical analysis of active shielding methods for space radiation protection," Aerospace Conference, 2005 IEEE , vol., no., pp.724,730, 5-12 March 2005, doi: 10.1109/AERO.2005.1559364
[2] M. A. Paluszek, “Magnetic Radiation Shielding forPermanent Space Habitats,” in The Industrialization of Space: Proceedings of the Twenty-third Annual Meeting, American Astronautical Society,36 Part 1, 545-574, 1978.