I highly recommend springing for Pocket Informant for a PIM replacement, if appointment setting and the like are that important to you. PI does SO much, including give you a really nice weekly view of things. I have a Today screen plugin called PIToday that is very configurable and lets me see what I've got going for however many days I want without ever opening up PI. The display is even shrinkable so I don't have to look at it 100% of the time.
As far as your hierarchical listmaking/outlining, I already recommended Listpro because it's so configurable. But I do know there are some outlining specific tools out there and I don't know what they are...let me do some research and get back to you.
As far as a launcher/button mapper, there is some functionality already built into the PPC OS. I keep my contacts and calendar buttons mapped to those functions, but my mailbox calendar brings up SmallMenu (hierarchical menu that is also really easy to navigate without the stylus), and my "Home" button that goes to the Dell Home utility goes to my Today screen. I had a similar set up on my iPAQ. I am fairly certain there are other button mapping utilities out there, so I am going to look into them as I am very curious myself.
One thing I have come to appreciate on my Pocket PC like never before has been Calligrapher. Not only does it offer excellent handwriting recognition (and I've used lots of text entry formats--the onscreen keyboard, Graffiti, Transcriber, Fitaly, the list goes on) but I have become obsessed with Pen Commander. Basically you can create macros for often typed text, program behavior, etc. If I write ypass and draw a circle around it, it types out my Yahoo! password for me. If I type net and draw a circle around it, it types out
http://www..net and leaves the cursor in the middle of the dots for me to finish the address. Writing ubook and drawing a circle around it fires up ubook. It's pretty nifty and I'm starting to write my own macros.
This week I plan to get around to reviewing my Dell and taking pictures and stuff. I've been too busy this weekend spending my bonus and bonding with my new toy.
Moving data over to the PPC...if you can sync the PIM data you have with Outlook, then you can just sync it up with your PPC through Activesync. As far as Shadow, I don't know.