Any way to change recommended resolution for all users on a Mac (preferably via Terminal)?
I've used this little app before and it works quite well. 

http://www.mowlem-enterprises.co.uk/screenutil/ScreenUtil_v1.0.zip

You'd just throw that into your image in your terminal path somewhere (/usr/sbin) then you can ARD shell command the terminal command you need or script it into the image.