1) I see, so that's why I didn't always get gold each time I had a certain number of points or reached the boss several times :p
2) Yes, I have been seeing the same screen ever since I started my playthroughs yesterday (from score 0 to 1030) such as the one below:
3) Ah, I see; that would make sense, seeing as it sounded like an experiment was taking place in a laboratory, or a building that's about to be infiltrated by some spy :)