Your theory is correct. So that shown 0 should have counted if you rolled any blanks. They are indeed meant to be difficult as the potential prize is greater than pretty much everything else there is in the game right now. Quite a lot of the events in the game are ones you can just blindly accept but this one I tried to make it so that you'd have to really consider whether you should gamble or not.
And what comes to the frog language, it's not expected to be solved. Those events don't even count as a real even (you still get another afterwards) and only give out some tips/hits if you've cracked the code. So basically just a pacing change where you might stop for a bit to ponder what is going on between fights. And I'm pretty sure the word game one is solvable even without knowing what they say...