I have never seen that last picture of Napoleon in a Russian Winterdress. It seems very usual, and because of that even more interesting and funny!

But I still have doubts that the pic shows our dearest Nappi

The slight full beard is also very untypical for a Napoleon

But maybe he carried it temporarily during his Russian campagn. Do you have any source, where this picture comes from ? I seem to remember that I have seen that site before, where this paintings are taken from, there are many great pictures of Napoleon and his battles, but at the moment I can´t remember it...
Yes, sometimes it´s better, if people don´t know about their coming future. The history has proved that almost all people, who went too far in their political career and were too radical or dictatoric will end somewhere in a tragic way (Exile, murder, suicide or execution), but despite of that such people existed, and now you can´t help in anymore, if you don´t like different aspects of their career, BUT: compared with later one´s of that "sort" Napoleon once had some good aims at the beginning, but then went too far, when his star ascended...
As to the arsenic thing, it is unlikely that he died of that, even when it was stated not only once, but especially the latest article (the link was also posted here) says that an ulcer, which became cancer later, was the main reason for his death. The ulcer was not caused by arsenic poisoning!