Likely you have a reason for using RSC… but if you’re doing this on the same router AND want the entire config replaced, Backup/Restore from the Files menu might be easier. The “export” file is designed to be “import” to into an unconfigured router - as you found out, you can NOT just do “export”, and then “import” same file back without adding code yourself. (And it unfortunate there is not an option to have RouterOS do this task for you)
But another good example of the needed “:if do={} else={} on-error={}” syntax that would have to be added to an RSC, is actually the default configuration for the box, which you can see using for the specific router you’re dealing with using:
/system default-configuration print
Another forum posting shows default config from the Audience: http://forum.mikrotik.com/t/audience-default-config/139424/7