The first part of your comment is based on what? It sounds more like a theory that you find in certain circles around the web, which are in my opinion mostly toxic.
And the 2nd part also needs a citation especially the villify part. While I am aware of the studies that you are referencing, they usually focus on sexual attraction. But relationships are not only based on sexual attraction.
As someone who vapes and has tried out some different products. Atleast here in Europe Juul was the only "pre-filled" cartridges product which contains nicotine salt instead of freebase nicotine.
Nicotine salt is much easier to vape and feels less harsh.
I.e I can easily vape 50mg/ml nicotine salt, while above 10mg/ml freebase gets uncomfortable for my throat. That might have been the reason for your dad coughing.
But I still agree, besides the salt/freebase aspect there can be different aspects of the ingrefients, each affecting health differently.
And the 2nd part also needs a citation especially the villify part. While I am aware of the studies that you are referencing, they usually focus on sexual attraction. But relationships are not only based on sexual attraction.