If the concern here is typing speed then you can make a script on a notepad to just copy/paste from into your chat. If you're playing in fullscreen this is obviously not going to work, but if you're playing windowed and can squeeze in a notepad somewhere, that works too.
Naturally, this won't help for on-the-go comments about what's happening live but it will at least help for introductions and the like. Just make sure it doesn't pop-up in front of the game as that gets rather distracting. As Severage said, commentary works wonders but not everyone are comfortable with it (or even can due to lack of a decent microphone) so it's understandable if it's an undesired path but it is something to keep in mind.
As I said though, having a script to copy/paste from for introductions can help prevent them from dragging on for too long.
Yeah that would work but what about spelling? Mabye I could cover the riting chat bar with a gear or something like that.