Most of your post is hard to follow and mixes a lot of topics. On the issue whether pain and social rejection have something in common, a highly-cited fMRI study [found](https://10.1126/science.1089134) that 

> In summary, a pattern of activations very
similar to those found in studies of physical
pain emerged during social exclusion, providing
evidence that the experience and regulation
of social and physical pain share a
common neuroanatomical basis.

Likewise a [newer study](http://www.pnas.org/content/108/15/6270) concludes that:

> rejection
and physical pain are similar not only in that they are both
distressing—they share a common somatosensory representation
as well.

An even more recent study has [challenged these](https://www.nature.com/articles/ncomms6380) though:

> Pain- and rejection-related representations are uncorrelated within regions thought to encode pain affect (for example, dorsal anterior cingulate) and show distinct functional connectivity with other regions in a separate resting-state data set (N=91). These findings demonstrate that separate representations underlie pain and rejection despite common fMRI activity at the gross anatomical level. Rather than co-opting pain circuitry, rejection involves distinct affective representations in humans.

Since most of the "hurtful" words on SE are of the kind that lead the receiver to experience some level of exclusion (not being "good enough" to be part of the site[s] etc.)... it seemed appropriate to mention this. Of course you can make someone feel excluded while being perfectly polite.

----

I'm less familiar with research on the effects of verbal abuse, but at least [one study found](https://ajp.psychiatryonline.org/doi/full/10.1176/ajp.2006.163.6.993) it has long-term negative consequences for some children. In fact there's [more than one](https://www.fsu.edu/news/2006/05/22/invisible.scars/) study with the same conclusions.

I don't know if there are studies on the extent to which adults are just able to shrug off verbal abuse. But there certainly are books arguing for not tolerating it in the workplace, e.g. Bob Sutton's ["No asshole"](https://en.wikipedia.org/wiki/The_No_Asshole_Rule) series.

And despite what your Polish Zen psychologists would like the reality to be, it just doesn't work like that in practice. Verbal abuse does have some effect, even on people (e.g. nurses) who encounter it often. Granted the effect is not huge. On a scale of 0 (no reaction) to 6 (extreme feeling), the average effects of verbal abuse are reported below:

[![enter image description here][1]][1]

There are a lot more studies on the effects bullying, which combines verbal abuse with other behaviors. Actually a problem with work-related constructs including verbal abuse is that there's perhaps a bit too many of them. But there's a slightly narrower one that was studied namely incivility; from [Hershcovis (2011) ](https://doi.org/10.1002/job.689):

> Incivility has recently emerged as one of the most studied variables in the workplace mistreatment [long list of citations]. It was defined by
Andersson and Pearson (1999) as low intensity deviant acts such as rude and discourteous verbal and
non-verbal behaviors enacted toward another organizational member with ambiguous intent to harm.
This construct differentiates itself from other constructs on several dimensions. First, it is defined as a
low intensity behavior. Andersson and Pearson explicitly argue that minor forms of mistreatment can
have a significant impact on employee attitudes toward the organization. In contrast, most other
mistreatment constructs are not defined in terms of their intensity, though intensity may be inferred by
their definition or measurement. For example, bullying can be assumed to be of higher intensity than
incivility because of its persistence and frequency.
A second differentiating feature of incivility is the explicit statement that intent is ambiguous.
Researchers in the workplace mistreatment literature have frequently debated the notion of intent. For
instance, Neuman and Baron (2005) argued that when defining mistreatment from the perspective of
the actor, intent is crucial. Otherwise, accidentally harmful behaviors such as being hurt by a dentist
during a dental procedure may be considered aggressive. On the other hand, from a target’s perspective,
perceived intent may be all that matters because victims will react based on their perception, whether or
not their perception is accurate. 

Nonetheless, the effects of incivility were comparable with that of bullying in a work environment:

[![enter image description here][2]][2]


  [1]: https://i.sstatic.net/DOhXP.png
  [2]: https://i.sstatic.net/1oWWi.png