They do use Blink (Chromium) internally, but it's my understanding that it is just bundled inside. I've run qutebrowser both as compiled and from source and not had any issues updating.

Qutebrowser includes its own adblocker, which must be activated once after install and works well enough.

It also supports both userscripts and python scripting. Although that takes more fiddling, there's a pretty healthy support community for it.