bsirons, welcome to MacOSX.com!
You'd probably be happier running the Mac version of Photoshop Elements 4. That's not to say that you could use the Windows version. Parallels has definitely made that possible. Maybe there's a "crossgrade" or whatever that would allow you to get the Mac version for less $. You're right, Photoshop Elements is excellent. I'm still at version 2.
As far as sharing your photos, I believe Parallels allows you to access your data from both "sides", Mac and Windows. I don't have an Intel Mac, so I'm a bit fuzzy on the details.
I'd suggest giving iPhoto a fair try before you dismiss it. It works fine for me. Of course, I "only" have ~1500 photos in iPhoto. Check out the photo books. They're fantastic. And I believe it is possible to set iPhoto 06 to allow you to manually manage your photos, storing them wherever you want.
From what I've read, people are really enthusiastic about Parallels' capabilities. But I think you'll ultimately be better off when you are more comfortable with OS X and run mostly or exclusively Mac apps. Just my humble opinion.
Good luck and have fun!
Doug