Hi,
1) yes the changeperm source is available, but you don't need it:
if you run on a Linux server, you will copy your iphoto library on this server. Then, you will perform all chmod by yourself for the apache user to have read access on them. changeperm is necessary on the mac, when the iPhoto Library is updated by iPhoto which modifies the permissions in such a way that apache can't access them anymore.

2) I don't know what this means. The error occurs in the php core. I find strange that this could be triggered by wipha.

3) your main problem: I use a mac command-line utility to resize the pictures and compress them (search for 'sips'). You either need to find a linux utility with similar functionalities, or use the php GD module, but this would imply more dev.

if you have questions, don't hesitate.
Good luck.