There are workarounds for many of these things, to differing degrees. The genius of open source is that you can even fork the browser if your target audience is geeky enough, while not exposing your friends and family to malware in their standard browser.
Forking something as complex as a browser is doomed to fail unless you have a lot of money. Sooner rather than later you won't be able to port patches and shortly after your fork will be riddled with security issues and incompatibilities.
