CHanging the mount option usually is not a problem unless the mount problem happens to be on one of the directory where you are installing softwares.
Your problem is generated by your /etc/fstab. Basically, it is telling that it cannot mount all the filesystems defined in your /etc/fstab. You should take a look at your fstab to make sure only what you need is in there.
Then once that is fixed, you shouldn't have a problem with your mount option in swinstall
Cooperation is doing with a smile what you have to do anyhow.