As this question Why is the SD-card mounted to "/sdcard/external_sd" instead of "/sdcard" (or "/mnt/sdcard")? points out, newer versions of Android often point the /mnt/sdcard path to internal storage instead of the SD card, and the location for the sd storage is not clearly defined and varies from device to device.
Is it possible to modify my phone so that /mnt/sdcard would actually point to the SD card instead of some arbitrary location on internal storage? (would this require rooting the phone?)
Since the new specifications are so vague about what the mount point should be for sd cards, many apps do not work properly, or have features (such as backup and restore or export) that are completely useless if the /mnt/sdcard path doesn't actually point to a removable piece of memory that you can move to another device.
mount
command/accessingvold.fstab
requires root permissions, but I'm not sure precisely how you'd go about this. Unrooted options will likely be very limited (if any exist at all, which I doubt, personally).