I have been running LMDE on a daily basis since September, and I have noticed that the system checks only my two data partitions after 30 loads. I have never seen it check the root or home partitions. Today I tried to clone LMDE before the deluge of updates, and Clonezilla confirmed my observation, refusing to clone my root and /home partitions because they have been booted 121 times with being checked. When I use "shutdown -r -F now", the system checks the two data partitions, but not root or home.
So far I haven't seen any problems that could be attributed to corrupted root partition, but with all the updates coming I am getting a little nervous.