>Is it really a feature to not be allowed to use non-webkit Chrome on my iPhone, even if it might unlock superior features?

Yes it is for many people. They do not want to risk the chance of their tool not working for some nebulous chance at a better experience. The vast majority of people are not tinkerer's at heart.

The rest of your questions can all be answered with "Yes", as long as the tool does as expected. We are literally all in the 1% of people just to begin with by even configuring software in the first place.