Incremental Search - This can be incredibly slow on large files and/or network mounted files. It can also interact with line wrapping and highlight search to slow vim to a crawl. So I think it makes sense to leave it off.

Tabs - That's the way god intended it. Stop trying to force your indentation width on me.

Stable working directory - This is how every text editor I'm aware of works. I can see use cases where you might want to change it manually or automatically, but I don't want to have to guess which directory I'm in every time I open a file.

Even some seeming no brainers like turning syntax highlighting on can be terrible because it doesn't work well with dark backgrounds or other random colour schemes.

Change working directory seans like the most stupid idea i ever heard... That would make:

  vim module/code.cpp
  :make

Not use the build system on the top level...