As it is I always use the following , for a long long time now and it's always exactly what I wanted.
First , yes, all must go to the master buss.
Mute the master buss to proof. Everything should be silent including effects.
"Select none" this seems to work 100% of the times. I found "select all" iffy with soft synths.
I use the default Sonar export. I've never had to change it, ever, other than I change 32 bit to 16 if I'm going to burn a CD. I don't even know what the default setting is! Must be entire mix?