So I don't expect this to be super long, but I promised I would post, so here goes:
France is going to solo. If they don't they should be ashamed of themselves. So what went wrong?
We have to go back to Spring 1906 and Germany's mind-bogglingly terrible moves. Barents Sea hold, Prussia hold, and North Sea disband were probably the three worst moves all game, bar none. After these moves, the whole board needed to immediately recognize that France was likely to solo. This is something that takes experience, but on skill that is necessary to playing the end game well is seeing what centers a power is likely to get. At that point, Germany's back was broken, so France was certain (certain!) to get London, Edinburgh, Kiel, Holland, Denmark, Norway, Sweden, and St. Petersburg before all was said and done. Munich and Berlin were still up for grabs. In the south, he already had Rome and Tunis and likely was going to pick up Naples that turn (although he has some other interesting choices- as we saw, he took Ionian Sea instead, which, of course, ultimately led to Naples). That's 18 centers even without Berlin or Munich! It was an absolute 100% priority to make sure Munich and Berlin were held and/or push back France in the south before he could get extra units down there.
Obviously, all the non-France powers didn't realize that or something, and so they collectively made extremely weak moves in Autumn 1906 as well. After this, France's solo was virtually guaranteed, as Munich was locked up and France was in no danger of losing centers in the south any time soon (and in fact would likely be gaining Naples).
It's almost silly to comment on moves past that, as the game is/was effectively over, so it's probably better to talk more about 1906. Does anyone have questions about what I said or what could have been done better, or things like that?
As far as the Russian moves, mainly my comment is that really any move that could possibly be helping to stop the French solo is better than that holds and cuts of support that he was submitting. A way the moves in Autumn 1907 could have been good is if they were paired with Germany having Silesia support Prussia to Berlin. This way, Germany could have disbanded the unit that would have been in Silesia and kept the army in Sweden. The next year, Russia could have shifted to Finland and St. Petersburg, allowing for all of the centers in the north to be held in 1908 for sure, 1909 most likely, and even possibly through 1910. This may have bought the south enough time to figure things out and push France back out of Italian centers and possibly salvaged a draw. Leaving Germany St. Petersburg would have been a terrible move, as more units are needed in the north, and Germany cannot provide them.