Been some time since I did the test, but I think it works like the following: the horizontal line acts like the horizon, so if you push the stick, the horizontal line moves up, just as the horizon would in a real aircraft. Left or right input will give you left or right, i.e. it is not reversed. I hope that makes sense!
You do get a practice one before the assessed one.
I have no idea what they look for. I did the test, and did alright (it gives you your scores) but someone said they got 80% of the shapes and colours wrong, but they still got a sim test.
As for the questions in the interview. This thread is good for practice, but I only got maybe 2 of the exact questions here. The rest were all re-worded. It would be worthwhile to concentrate on your specific examples of teamwork, leadership, over-coming adversity and so on, rather than answers to the specific questions.