A test scenario is proposed in D25135, covering different cases for issues #1 and #2.
Apart from those, the 3rd issue cannot be tested due to the widget "privateness":
- Search type (`Filename` / `Content`) is selected correctly
- Filename: `baloosearch://?json=%7B%22searchString%22:%22filename:file%22%7D`
- Content: `baloosearch://?json=%7B%22searchString%22:%22file%22%7D`