Hmm... I wouldn't agree that you need to use DNN source to work with WAP? When I advise it, it's only because that gives you additional debugging help (having the source code helps you traverse your module into the DNN framework, and thus debug certain problematic scenarios easier)... You can also work without the source, and only deploy your modules to the central DNN installation for debugging and testing (my tutorial actually does that, it only uses the start kit and the source on start... but that can be avoided easily)
As for the beginners... I agree that not having to write your own data provider projects is a nice touch (actually when you've mentioned the idea some time ago on the asp.net forums it sounded really nice to me), not having to use IIS is also a nice touch... but for me things like that are of short term... simply because you start as a beginner (I did for DNN a few years ago on DNN 1.x and it was a pain to start developing.... although even then I was an experienced asp.net developer), and at that time things you mentioned are GREAT, but soon after you raise above the beginner level, those things become obsolete because you start thinking about smarter ways to write OO code, smarter ways to test the code, etc... then you come to O/R mappers, REAL code generation, real OO code practices, services, DDD design, etc... as well as wanting to have a FAST development enviroment that doesn't burden you with projects you don't need....
On the other hand, I agree that if you want to build a small solution (e.g. Guestbook) the practices you advise are quite enough, quite good, VERY easy to follow, and especially EASY to start with... that's why I am glad that there is a person like you who helps people get to a higher ground and start developing modules.
Cheers!