Technology is a many edged sword. It allows new possibilities but also demands responsibility.
What should we do? What shouldn't we do and why?
How should we decide what to do? Who should decide?
Joe, I come down on the side of freedom to learn.
All avenues of learning, all techniques of gaining knowledge, should be explored.
Once something useful has been learned, something which can be used for good as well as for ill, then I think it is appropriate to ask the type of questions you raise.
I would suggest that it is wrong to use any technique to deliberately harm others. Yet it is OK to use that same technique, in any way which benefits others.
This is a simplistic view, I know, and I state the obvious here just as a starting point.
To go a little further, I see this as the same type of question that exercised the first couple of generations of members of the TS following HPB's generation. I'm using "generation" loosely here, more in the sense of teachers and their students; those taught by HPB being first generation, and those taught by these students being the second generation, and so forth.
During the time I speak of, many members of the TS arrogated to themselves lifetimes of power and prestige, and thereby claimed high rank for themselves. This caused something of a scandal, and from that point on, all new members were carefully and thoroughly taught that they were beginners, just like everyone else, and that it is wrong to claim or seek 'powers', much less demonstrate them.
So the current thought is that we students should never seek to develop any abilities, but merely meditate and patiently wait for the abilities to appear.
I don't agree with this teaching. I think that every student should strive to develop whatever natural powers are within his or her reach in this lifetime.
The real issue, coming back to your questions above, is primarily about HOW these abilities should be used, once gained.
Not whether; but how.
Thus, to repeat your question above, How should we decide how to use them?
And who should be the ones to decide?