The rename problem is probably related to the depth of the folder structure.
Unpacking an archive will keep its folder structure. If this leads to the images being in a folder three steps down from the gallery folder, this could make the script to not find images.
I'm not 100% sure as I don't remember and I can't check it now. I will investigate...
As regards the second problem, if you don't experiment force closing, then the memory fix worked!
Anyway, there is still a last possibility: we hit the critical size!
As I told before, komic is way bigger and more complex than any other WAF (IMHO) and this is not a plus when memory is a critical aspect!