But wasn't Sankt Petersburg the true capital? I suppose Napoleon would have greater changes to capture courtiers if he went there.Moscow mattered to Napoleon because it was Russia's old capital and he felt capturing it would achieve his war aims of enabling Alexander to remove his "bad advisers" and seek peace.
-what is TLDR?Well, if you hadn't been all TL;DR, then you would know that I said it would be much, much worse. Napoleon would be exposed to British bombardment and his supply lines would be right across very uncomfortable territory. Furthermore, he'd be vulnerable to encirclement.
- naval bombardment? even if the British do indeed break into the Baltic, we are talking about 18th century ships of the Line, not the Yamato! The only way they can inconvenience Napoleon's Army is if he insists on sticking to the beach all the way to Sankt Petersburg
-as for the "unconfortable terittory": why would it be any more unconfortable then central Russia? at least he would be marching through lands that have only been taken by Russia relatively recently, so theey might be slightly more "civilized"