Questions, possibly bugs

Hi

We are currently evaluating SpiraTest to make sure it is the product we want to use, and have come across a few issues that may be bugs or may just be consequences of a design strategy that are different from what we are used to or expect. 
The main problem is that these issues makes me doubt what I'm looking at.

1. I can add test cases to a release, so why canGÇÖt I add test sets to a release?
What is the philosophy behind adding test cases to a release but having to execute test sets?

2. Test coverage column in release list says GÇ£No testsGÇ¥, but the Test Runs tab on the release contains a passed test run.  Clear Filter and Refresh makes no difference.
What I did was execute a test set and specify the release.

3. List of testcase under Testing -> TestCases seems to be a little weird when selecting a release.
When selecting the release that says GÇ£No testsGÇ¥, some of the folders in the test case list disappears.
When selecting another release they are shown.
When selecting GÇ£All releasesGÇ¥ they are shown.

Best regards

Michael