Metal9966,
I don't have enough experience (yet...) to offer qualified advice on your #2 point, although it is something I'm too very interested in exploring.
However, as far as #1 is concerned, I believe you have not too much to be worried. One of the beauty of the Zaurus is that you have to go "under the hood" only if you want too. Granted, as a PDA it is certainly not the most polished around, but it can be used as a decent PDA and be "unleashed" to full power when you want.
To make an analogy, I see it pretty much like chosing a car: If you only care about being transported from point A to point B, almost any car can be a good fit. However, if you are the kind of guy who likes driving and having fun while still going front point A to point B, then you get something sportier. The sporty car will still carry you from point A to point B, but the possibilities are up to a whole new level...
Aren't few things in life not just about the destination, but rather about the journey? Get a Palm or a PPC and you will have good PDA functions, some advanced functionality and you may even learn a thing or two in the process. Get a Zaurus with Linux and your learning opportunities become virtually endless, not to mention the fun factor.
I like to think of my SL-6000L as a personal trainer for my brain...
And by the way, I'm talking as an hard core Psion user who has only recently entered the Zaurus universe. While the world was going Palm in the early 90s I got a Psion 3c. Few years later Windows CE clamshell machines arrived, but the 3c stayed. Few years ago the PPC started and I decided to upgrade to a Psion 5mx...
Then Psion left the pocket computer market and I would have probably ended buying one of those "hi-end" PPC, had I not run by chance into the SL-C700 announcement while running a google search for a "PDA with keyboard". Man, what a discovery!!!!! Just thinking of the possibilities opened by such a platform was mind boggling.
For at least a year I have been waiting for the right opportunity to get one of those Zaurus Linux boxes. When I saw Amazon slashing the price almost 50%, that was it... I ordered the SL-6000L and I'm loving it.
Give it a try, especially if you already know Linux and want to do programming. What's the risk? You can easily return it or resell it on eBay in few months and probably even make some money in the process!!!!
Enjoy the journey....