Yeah, the folder doesn't operate as a folder... I mean, if I "show contents" I can eventually arrive at my iChat icons, iPhoto library, etc. but the Pictures folder responds to a click by taking me to a Terminal window.
An Apple rep is suggesting I do a clean re-install. =( Ugh.
In my "iPhoto Library" package, I have no Pictures folder, or iPhoto library. I do have "Library.iPhoto". So, I still can't entirely picture (no pun intended) where you are. I am assuming you went into your "Picture" folder - which is a normal Finder folder, then went to the
package "iPhoto Library", used "Show Package Contents", and deleted some things from within it.
What does iPhoto do when you launch it? Are your images still there? If iPhoto is still functioning normally, then the fact you can't launch it by clicking on the corrupt "iPhoto Library" package is somewhat moot. Just don't launch iPhoto that way - at least, until the package is somehow repaired.
You wouldn't, by any chance, have a backup (Time Machine, perhaps)? Had to ask...
To answer your question about which files are needed for a working package: I have about 30 different files and folders. The specifics won't help much, unless you still have what you tossed. If that were the case, then we could help restore the package.
The only other thing I can think of is to recreate "iPhoto Library" package - your iPhoto events/albums etc. Make a
copy of the "iPhoto Library" package, then delete the original. Open iPhoto, and reimport your images from the "iPhoto Library/Masters" folder (inside the package). This should recreate a functional "iPhoto Library" package, though all your metadata added (in addition to the original image's data) will be lost.
I'm assuming you've only been using iPhoto for a relatively short time (mine goes back to where iPhoto stored images differently - 2006, I believe). So, all your images
should be in the Masters sub-folder.