#1 - you can hit info to cycle through the various menus, and finally to turn it off altogether. One click --> other menu ---> electronic level ---> turned off screen ---> back to status screen
#2 - wouldn't know as I have image review disabled altogether. I guess you could just set it to a shorter duration, otherwise what you're doing right now is basically it.
#3 - I've never had my battery run out (LI90) so.......
#4 - nope, unfortunately not, and this is the same for all dSLRs. Think of movie as basically a constant-picture live view: the mirror is flipped up to project light onto the sensor, so no light enters the viewfinder (from the image end anyways)
Hope that helps