I understand your reservations but the thing to check for in any of these apps is the ability to export from the App - as that's how you migrate to other options.
iPhoto will allow you to export from the app into a Folder tree matching your Events and Albums set up.
If that's not granular enough then apps like iPhoto2Disk or PhotoShare will help you export to a Folder tree matching your Events.
At heart though, if you're going to enjoy iPhoto (and similar apps, like Picasa, Aperture, Lightroom etc) you have to make a distinction in your head between your Photos and the Files that contain them.
The illustration I use is as follows: In my iTunes Library I have a file called 'Let_it_Be_The_Beatles.mp3'. So what is that, exactly? It's not the song. The Beatles never wrote an mp3. They wrote a tune and lyrics. They recorded it and a copy of that recording is stored in the mp3 file. So the file is just a container for the recording. That container is designed in a specific way attuned to the characteristics and requirements of the data. Hence, mp3.
Similarly, that Jpeg is not your photo, it's a container designed to hold that kind of data. iPhoto is all about the data and not about the container. So, regardless of where you choose to store the file, iPhoto will manage the photo, edit the photo, add metadata to the Photo but never touch the file. If you choose to export - unless you specifically choose to export the original - iPhoto will export the Photo into a new container - a new file containing the photo.
Before you try this
From what I understand, iPhoto provides a way that lets me use the best of both worlds, i.e. retain the originals of the photos in my own folder structure, and still record them in its own catalog with all the logical classifications in events, albums, etc
.
which is called a Referenced Library, you might want to consider somethings:
You can use iPhoto in two modes: Managed (which is the default) and Referenced. The difference is that with the Managed mode iPhoto is responsible for the file management: importing, storing, deleting and so on, are all done via the iPhoto window. When you do this your files are stored in the iPhoto Library in your Pictures Folder.
With a Referenced Library you do the file management. You move the files from the camera, you put them where you want them, you then import them to iPhoto. iPhoto won't copy them into the Library. For deletions you first delete the file from iPhoto, then find it in your fling system and delete it there.
Some people reflexivley want to run a Referenced Library. They want to know where the files are, they want to be able to access them and so on.
Simply, there is no good reason to run a Referenced Library in iPhoto. Here's why.
1. It's more work. With a managed Library importing is a one-step operation, with a Referenced it's several. Ditto with deletions.
2. It bestows no extra capability whatever. No added features. Nothing. Everything you do with your Photos you still do via the iPhoto Window - accessing files, editing, sharing, whatever, you do either with or via iPhoto. This is just dumb storage. Simply, you never access your files via the Finder if you use iPhoto. It replaces the Finder for anything to do with your Photos - think iTunes for music, Contacts for Addresses. It's the go-to app for your photos.
3. It can cause big problems in some circumstances: If your library grows and you want to move it to an external disk, you will have problems. If you have the library on one disk and the photos stored on another you may also have significant problems. Even migrating to a new Mac can cause problems. Why? If the path to the files changes then iPhoto has no tools to repair that. So, your disk fills up and you move your filing system... iPhoto can't find the files. And it tells you. For every file in your Library. All of them. Every one. You rename a disk, you change your account name when you move to a new machine etc., you will have problems.
None of these issues exist with a Managed Library. Moving it to an external, migrating it and so on are simple and painless.
Remember too, that with a Referenced Library there is still no way to access your edited photos except through iPhoto.
The best advice I can give you is to create a Library, import 100 pics and explore. iPhoto is not for everyone, and there is a (small) learning curve involved. Even if you decide to use iPhoto, I would still maintain my current system in parallel for a while, until I was sure that iPhoto was the app for me.
I would also recommend that approach for using any other app too.
Regards
TD