He definitely wasn't at fault, but in my uneducated opinion he should have avoided being at such a position. If the championship was closer I would agree with the move. But he should just try to play it safe and consolidate his second position in the wdc. Incidents like this cost money in repairs, decrease his standing with the team and gave free points to his biggest rival.
Well, on one hand that is certainly true, on the other he probably just wants to prove himself. And from the replay it didn't look like he even touched Hulkenberg but he just got bowled by Ocon. So as much as I agree with your point, that was just really bad luck.
For sure bad luck. Though if he got information that the softs were going off he should have reconsidered that move, imho. If he wants to stay with Red Bull he just needs to bring in points and not crash.
Even in that case it doesn't make sense, imho again, either he needs to show smart racing if he wants to go elsewhere. Or he again needs to maintain second if ge wants to quit. We can all say he had no chance this year but second in the stats is still second.