As someone who hasn't read any of this thread except for this post, the main problem is that your definition of determinism doesn't seem to be the standard. Even if some events are determined by random chance, that still isn't your choice, right? I've never seen anyone say that determinism is when you can predict all of your choices before you make them.
Like, fundamentally the two options are
1. The universe is set in stone from the beginning and none of our decisions could have ever been any different.
2. Some of the decisions we make are decided entirely by random chance.
It seems to me that both of these fall under the label of determinism. I considered myself a compatiblist until recently, but now I'm mostly just not completely sure.
Edit: Hmm. Guess I'm just repeating almost the same thing as my post earlier in this thread. Oh well,