Maybe there should be some mapping of device names depending on the source of the export (which is in the header), so it knows when importing a config from another router which transformations have to be made on the input before applying it.
yup, it's called man-hour-notepad
But adding on to your ideas about partial import:
What if Mikrotik exported each section of the config (e.g. /ip firewall export file=firewall; /interface ethernet export file=ethernet...... )
inside one ZIP file
(as i understand, many sections are already internally stored as separate files / pointer lists, and some other gore)
that would have two advantages:
one: filezise for big-config exports would drop dramatically
two: as sections would already be neatly separated in different RSC files inside the one export "zip", one could easilly have the command "/import sections=a,b,c", or "/import sections=!lcd"
without even having to parse the whole extent of the config