Answer to part 3:

I still believe that accessing those stored thumbnails is preferrable. Performance is optimum for every user, the page load instantly and the cpu load on the server is very low, null due to computing the image. Using wipha I noticed very big delays and 100% cpu time with up to 4 httpd instances.

thumbnail mode:

- sudo fs_usage | grep iphotod | grep open

gave me 24 thumbnails in less than two seconds

- sudo fs_usage | grep httpd | grep open

gave me 15 thumbnails (uncached) in 31 seconds (tested twice) generating a massive flow of messages

Please seriously take in consideration the chance of using the already present thumbnails, it requires even less computation and resolves any OS dependancy.