Yes, taking all the "I spent some time not-writing so I come back refreshed for NaNo" energy and putting it into something that isn't NaNo might be a little counter-productive.

Ooooh, yes. Having a jump on that would be good. Much easier to write on a computer than in a notebook. In the car. But at my support network keeps telling me (that sounds like a NaNo-Anon or something, it's really a month-long NaNo feature in a comm I'm in), as long as you're still going at it, you're doing it, and that's better than giving up.