I agree with the explosions! Just like you said, throughout the development process the explosions and the unavoidability of it (due to it being snake) has been something I've tried to manage (However it seems to limited avail)!
For the circling strategy! The increasing length of the snake is meant to tackle that along with the smaller spawn buffer around the snake segments! To encourage players to go out of their way to collect stars. As for movement, I believe I have implemented a smooth U-turn such that you won't collide with yourself, however I will improve upon it more in the future!