Define rip Safari out of Mac. Safari is nothing but a shell for WebKit, the HTML renderer. (+ JS and a lot of other things.) You can probably delete Safari no problem, although it'll probably reinstall with system updates.
You can't pull WebKit out of Mac since it's used in all kinds of programs. The least of which is iTunes for their iTunes Store.
Nothing. If you try to delete WebKit, though, Dashboard and a host of other apps will stop working (Adium, iChat, some aspects of the finder, Mail, etc).
In terms of operation or in terms of updates? In terms of operation, everything continues to work fine (where everything is not literal, but nothing significant).