The fact that modules break, etc. imho is a Good Thing - in following the rule of "failing fast". Since, you dont need to change/hack the drupal core to do anything complex, if a module is breaking it is typically highlighting incompatibilities with other modules (99.99% of the time). Giving a white screen on module install is exactly the right time to have it happen, rather than 1 month later, when it goes live.
I completely agree with you on the admin UI part - I had just two main peeves with Drupal 6: Postgres support, which got fixed in Drupal 7 and admin UI, which is not yet done.
I also wish that they provide a couple of starter "installation profiles" - blog, wiki, corporate, etc. - enabling a quick start for 99% of the population.