I managed to right a dissertation on MacWrite back in 93 without ever once thinking it needed more functionality.
I'm guessing it didn't include a spell checker?
“Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying.”
From Clarke, but that was quoted at the beginning of some really brain-cancer-inducing movie somewhat recently. Perhaps this is why I cannot recall which movie.
Can I run a WebKit based browser on FireFox OS?
You can swap it out if you've jailbroken, or simply write your own app with any engine you like (which works fine for personal or enterprise use).
This point I've never quite fully understood - people keep complaining about how insecure Android is (which is a debate for another thread). Yet when discussing shortcomings of iOS, the answer is always "jailbreak" (which might or might not be available, tethered or perhaps not). As it is, at work I've been developing an app for iPad that is HTML5-based. And the performance is worse than what Mobile Safari would offer. If you want your HTML5 app available on the App store, this is a fact you'll just have to accept. This is also the reason you shouldn't expect Firefox on iOS anytime soon.