No, most of your inquiries can be accomplished without code. One of the major tenets of Test Studio is to keep coding to a minimum and only resort to it when you absolutely have to.
1. This can be done by targeting a Test Studio Test List with ArtOfTest.Runner or a Visual Studio Test List with MSTest. In the Test List Settings you'll target a specific BaseUrl. So for Test Studio test lists you'll have one list per BaseUrl, and for VS test lists you'll have one test settings file per BaseUrl.
2. We are avid proponents of this approach and offer the Test as Step feature.
3. This cannot be done as stated. However I can think of a few approaches to achieve the same goal, mainly with our Data Driven Testing feature. With the user name and passwords steps data bound in the Login test, you could employ a solution from our Dynamic Data Binding article and swap the data source based on environment, for example.
4. ArtOfTest.Runner and MSTest, both mentioned above, can also target a single test. What's more likely is you'll have various test lists than contain certain tests in a specified order, and call your desired test list from the command line.
the Telerik team