I'm all for efficiency but based on my experience reading the code people write, the last thing we need is getting them to type faster. I'd prefer if some people slowed down a whole heck of a lot to think more about what it is they're doing.
I always thought autocomplete suggestions and snippets preserved brain cycles. IMHO if you prevent developer exhaustion your code gets better-looking and more maintainable.
But then again I'm a single developer, working on personal projects...
No need to use the shift key. At the levels of efficiency that a good language can reach, this matters.
Also, dashes match established lexicographical conventions better than underscores because dashes look like hyphens.