Can't mount cache errors can be caused by an incorrect recovery.fstab file, which basically means the incorrect mount points are used. Had that issue on my phone trying to install CWM recovery, but it was incompatible with my phone giving the same errors you described. You'll probably have to find a good recovery.img, and test if it's working. You can fastboot boot recovery.img without flasing as well.
By the way, to really dig into this problem, it's possible to extract the recovery.fstab file from the recovery.img file you're using, and see if this matches your /proc/emmc.