Hello again acidicglitter,
This is all a "MOO" (My Opinion Only)
Some things may be worth keeping in mind -
The theremin is NEW - its been with us for <100 years, and has been mastered by a tiny number of people... There simply hasn't been enough playing of this instrument for a "best" standardized technique to evolve IMO.. Its not even certain that there is a "best" technique or that one will ever evolve -
The present techniques are mainly developed by musicians skilled on acoustic instruments - IMO, they have carried these techniques over from these instruments and adapted them.. And this is fine and great - FOR THEM!
But IF there REALLY is a "best way" to play a theremin, I think the discovery of this "way" or the development of such a "technique" is likely to come from someone who utterly understands capacitive interactions and instinctively uses the many dimensional aspects available, rather than from someone who carries the baggage from some (comparatively limited)* acoustic instrument and adapts this.
Having said the above, it is true that violin / cello players are generally far quicker getting "into" the theremin than other musicians - But I think this is down to the fretless / keyless / infinite untempered nature of these instruments..
But in reality, IMO, the theremin has very little in common with a violin - there isnt an "invisible string" - IMO a better analogy is that there are an infinite number of "invisible strings" radiating in all directions from the antenna, and the "stretching" of each of these strings is determined by every ground point they link to (every conductive object in the theremins vicinity) and the sum of all these "strings" determines the pitch... the further from the antenna the object/s the "strings" connect to, the lower the frequency they contribute.
So yeah - perhaps start by treating it like some sort of ethereal violin - But keep in mind that for every way one can obviously influence pitch, there are a multitude of equally usable other ways to influence it -
IMO, if what you are doing causes any real physical discomfort or pain, DONT do it! - There will be a painless route to achieve the same result just as efficiently! - I personally know one pro thereminist who has caused themselves damage, and IMO it was needless.. Sweat, effort, dedication, good pitch recognition - yes, musical education and experience playing other instruments is always helpful, as is having a personal tutor, but not IMO essential... Blood and/or tears (from physical pain or discomfort) IMO says you aint going the right direction!
* I need to clarify this - I am talking about "dimensionally limited" only! - In every other way I think it is the theremin which is more limited!