I'm reading the OP's second post again, and it leaves me quite confused. But that's probably because ChangNoi doesn't have a good understanding (yet) of how to do things efficiently in OS X. I mean, it's one thing to flat out say that you don't like iPhoto for x,y or reason z... but to say that it won't do what he wants it to do is entirely another thing.
Is it more bloated than a browser type image viewer like Bridge? Sure. But to say that it doesn't have a proper crop tool, or that you can't upload your edited photos to a certain website is plain wrong. Same thing applies to Aperture, LR etc..
As for using Preview to search for photos, you most certainly can do so without issue, if you allow the time for them to actually load within it. ChangNoi, like you, I actually keep my photos in a folder hierarchy. This habit carried over from my Windows days. But believe it or not, I am able to maintain this way of working, because Lightroom (Aperture does this too, to an certain extent) allows me to create further folders within parent folders (pre existing ones at that) either as I'm importing new photos, or whenever I want!
Anyway, let's say that you have a folder structure set up in Finder, in the Pictures folder (you really should always use the pre-set up folders that appear standard on every OS X install) named : Places. Then let's say that within Places you've got : "Asia" then within "Asia", you've got "Burma" and so forth and so on... Well, If you really want to use Finder and Preview together, you can. Just go to the folder you want and then hit Command+A then just either tap on one of the photos, or right click and choose open with>Preview. But the double tap on a photo will do the same thing. And it will look like this:
And that's just one of the views. You can customize the toolbar and get some really great things going on. You can also make the thumbnails smaller on the side
And you know, you can also select all, hit the space bar and have preview open them all in a slideshow that you're able to control. Once you've found what you want to work on, you can just open that one in preview with one tap/click. That's why I love OS X. So many different ways to get to your destination.
P.S. Pardon the él cheapo EVO 4G pics! It will never happen again.. literally. I smashed my EVO a few days ago.
Doug