You were asking if you can break your splint during the night? Well, I read somewhere in a literature, that patients may bite large teeth marks into a night bite guards and can fracture appliances. But, I think that would mean only if you are really clenching hard or grinding hard at night. I had my bite plate for 8 years, and I only clench some...
I don't think of myself as a hard clencher. I think if you want to know how much of a clencher you are, look at your bite plate... are their large teeth marks on it? And when you go to your Dr. for adjustments, ask him if he can tell by adjusting your plate how much of a clencher you are.
Because I had the splint for so long, I am thinking of moving into a different direction... maybe a NTI.
But you sound like you only had the splint for a short while, is that right? And it sounds like you are making some progress with it. If I were you, I would stick with it for awhile, and if you find you are having more problems with your jaw or something, that might be the time to change to something else.
I hope I have answered some of your questions. I am just telling you from my own experience.