PHP is also insecure from it's core functions because its dev team shuns proper security practices.
Anyways, anybody running a serious imageboard off a free host has yet to learn the horrors of bandwidth and CPU load restrictions. Even so, there are a lot of free hosts with perl installed on the machines in their datacenter, even some running python, making the whole "well some people have to use PHP" argument void.
I really implore you not to continue this project, but if you decide you're going to, just don't add stickies. We don't need another kusaba clone on the net.