Ah, pardon the misunderstanding

You, sir, win all of the internets.
... Then again .... I'm an idiot .....

While you are correct about many of the concerns from the stemming process, I was mainly talking about somatic mutations (like those caused by gamma radiation for example). The statement I made previously about these somatic mutations propagating no more in stemming than in breeding is still true. Also, the proto-oncogene concern is one that current research is already working toward limiting.
My main concern with your statement is the argument that stem cells are MORE susceptible to random mutation than somatic cells. This is simply false. You argued that decreased activity is a protective attribute than for stem cells. In fact, most stem cells in the human body are LESS active than somatic cells as somatic cells do the work and (monopotent) stem cells like osteoprogenitor cells are mainly there to replenish and preserve genetic information. It's a biological axiom that sex cells (sperm and ova) have the highest importance in preserving genetic integrity and that's what we see experimentally: the sex cells have BETTER preservation of information, not worse.
.... Then again ..... I'm an idiot ....

Biochemist medical student here. Propagating genetic errors is certainly a concern here, but the same concerns exist for genetic transfer in breeding generally. While skin cell are exposed to more radiation, the cells preferred for sampling here are typically from buccal (mouth) sources or are relatively deeper than the layers where most melanoma form.
Honestly, the more prime concerns are with imperfect "stemming" or imperfect conversion to heart cells.
Then again ... I'm and idiot ....

Forget the arguments against dynamic languages because you said you're doing this as your own project.
Forget the arguments for javascript because you're asking for a language to 'become native to'.
The Python language is great and community is awesome.
Then again... I'm and idiot.....

Yes, in the sense that they're using it to try to determine which parts serve which function. Certain areas are dependent on the function of other areas, like Broca's area (mouth articulation for speech) being dependent on Wernicke's area (Word association/searching).

Then again.... I'm an idiot.....

This is deep brain stimulation. They're running a constant or alternating current, not producing bursts of electricity or a 'shock'. I've administered the modern, anesthetized, calibrated version of electroshock in my medical training and this procedure described here is also very, very different.

This is much more analogous to overclocking a part of the brain by preferentially stimulating it to work harder. This may be used to improve performance but those applications are still far away. This is most useful as a diagnostic tool or even more likely as a research tool to try to understand what various parts of the brain do.

Then again.... I'm an idiot.....