We don't have much validation on `set` - people can use it to make their own settings if they want - so just because it was accepted doesn't mean that it worked in the way you thought it would...
In this case it's because I misremembered the setting. You want `:set hintnames numeric` instead : )
Regarding bind: as I said, it maps sequences of keys to an ex-command. Your attempt is a sequence of keys to a sequence of keys. The correct invocation is `bind w tabnext`.
We left ctrl-c unbound so it could be used for copy, not least because I know it would annoy the hell out of me. You can rebind it with `bind stop`, but because we only have access to pages after they've loaded a bit, it might not quite work as often as you'd like.
Ctrl-I will only work if you have `:native` installed, and, if you're on OSX, an editor I thought to add, which I think might just be MacVim. I'd hope it would give you errors if any of the above was untrue...
We definitely aren't at feature parity with Vimperator. Some stuff Mozilla just won't let us do (e.g, emenu), other stuff we can do but haven't got around to it yet (accepting keyboard input on privileged pages - we have preliminary approval for extending WebExtensions).
I'm glad I could help. There's `:tutor` which is fairly short and probably the most user-friendly way of digesting general information, and there's `:help` if you fancy a very dry novella; there's also somewhat hidden help pages for settings and commands for use in insert/ex mode, the latter of which I can't remember how to access. I think there's a link hidden on the main help page.