Hi Tilmann,
Yes, looks v.useful. One of my guys is currently looking at it as is pretty interested. I suspect he'll want to pursue this with you further.
Regression tests... absolutely! Apart form anything else AD left quite a few holes in acs4.2 so I guess for you could easily look at regression in this case as being acceptance testing 😉
I'm also pretty interested in your installation script. Quick, simple, automatic installation is (IMHO) a great asset for any product. Its usually the first experience a new user has, and can therefore really turn them on (or off) to it. I'd be happy to pitch in and do what I can if you wanted to send it over/post it up somewhere.
Cheers
Simon