Cool, you actually noticed the bonk mechanic (exactly the same name I called it in code too) and the correct use of it. The bonk failing the throw was there pretty much since the beginning but it was actually quite a late addition to add that re-randomization to it too making it a (pretty much the only) defensive tool.
Yeah definitely the pass/throw UI could be better. Just not quite sure how. 😅 I myself too did quite a lot of accidental bonks while trying to quickly pass to the other dice right on front. I guess one easy improvement at least could be to tweak the throw button placing so that it doesn't cover other dice so much.
There is no nudging on RNG going on at all so yeah, the bigger dice are obviously outclassing you by a lot and you'll require some good luck to take them out (and not get one round wiped by em). I think for the current state of the game it's fine but if I were to continue it, I think I'd add more of a progression and skills etc which can balance out the odds.
The AI does indeed always pick the biggest die they can take out. It's not perfect by any means, at least it doesn't take bonks into account and sometimes loses track of all the passing/moving steps. I thought those (and the big advantage of going against D4s on the early stages) were enough to balance the AI. Usually I add some random chance for the AI to do "derp" and pick some option randomly which I can then decrease to slowly increase the difficulty but didn't feel like this needed that treatment.
Thanks a lot for the detailed feedback! ❤️