Here are my responses to those Qs I can answer:
2) People will probably call it dangerous (if you are driving and doing this at the same time), but, with that caveat, it is possible to use the cursor to enter a new destination or find a POI while driving.
3) I don't know about e-mail dictation. I found the voice command thing a little hard to use at the beginning and rarely use it to enter addresses. My most common use for it stop guidance on the NAV. I just didn't take the time to figure out what else it can do.
4) I've never had to pay for traffic after 2 years (knock on wood). The free sat radio ends after a year.
5) Depends on how you drive.