As stated in this feature request, we work agile and the tester gets new applications versions (almost) on a daily basis.
The tester does not know which objects have been changed/deleted. And does ...
Regarding the scan without a run question, there is a time issue here. Even if time is not the most important point in automation, running a whole campaign can take hours. If you run all your tests, you have then to wait hours before updating your tests and run them again. With a scan option, you may declare the different screens of your application, with a path to it. Even with a lot a different screens, this doesn't seem to be lot of work as the path shouldn't evolve so often. The scan can then be performed in a few minutes for basic situations. As the goal here is to perform the tests asap, with reliable results, running the test campaign twice is not an option imo...