I am so scared of aliens.
I have never seen one, so they never did anything to me either.
But I have heard stories of alien abductions, mostly in the X files.
Since I don't know about aliens, and just to be in the safe side, I am scared, and recommend to other people to stay away from them.
Sounds pretty much like these new security concerns:
images in the bmz-cache are encrypted, so it does not matter to what security level they are set.
If you use some free security tools like the Hacker toolbar, a free add-on for Firefox, or even the Linux CD from backtrack-linux.org, you will see what I mean.
Try to find an entry point there.
755 works for most Linux servers, I don't know if for all.
Just to feed the paranoia you can set to 755 recursively your bmz_cache, IH2 does NOT set permissions for folders.
Regarding the coders, yes they are dead people, and bad too, addicted to forks.
However, the last incarnation for IH2 has been written and tested for Zen Cart simply because...there is no IH2 plugin yet for that other bad thing they indulge in.
But stay tuned and you might soon find one.