Well, it is complicated. With 15 players, you can have quite some strange stuff happeneing. First thing: It's 1938 scenario. War started mid 1939 iirc. No one build IC. It was mid 1943 when we ended.
You should see the plane statistics, even i had 60 planes. Germany had 200, UK 75, SU only 50 or so though. Planes do rule Monday games.
First about Italy: Yes, it's awesome to see it this big. But it was only achieved due to all of our peeps working together. It's scattered with Airfields for our bombers as well
Second about me: My IC isnt that high. it was 280 back then i think. At that point i finally had more than the US. Also my liberation policies: After Fall of the Dragon, i annex China, then release guangxi as the successor and it gets the south with barely any INdustry and i give it more territory up to the yellow river. On the top left of CHina is the green former puppet of Natchina, not commie china.
Third about first Edit: That's brazil

Only with the help of brazil we were able to get panama, through which i could sail through. You should also not that Brazil provided at least 50 divisions for the US invasion. I didnt nearly have as many as i needed to invade them alone, let alon have many mobile divisions. After Africa Italy joined the frail as well. Germany was well occupied.
@Edit2: No that's Brazil as well. At a point, Spain controlled NY and Brazil new england.
@Edot3: Germany and SU had been at war as long as 3 years back. Because of the german landing in the UK, Germany had about 60 troops occupied there. Then the SU dowed, because it looked like Germany was gonna win the war in 1940 already. It took Königsberg and a couple of provinces east of it, but got stopped cold due to a stahlgewitter unleashed by German stukas. Taking one province at a time would cost the SU 2-5 infantry divisions. It was that bad, believe me. Also Germany had a biger mobile reserve which actually encircled and destroyed some of SU's divisions, but couldn't afford to go far into SU.
As far as my effort in Siberia is: We have had a war since 3 years, but a non aggression pact agreed upon by both sides. I needed it to free forces to invade the US. By the end though i had a limited offensive, but only took vladi i think.
Also Scandi had great power issues and hence invaded the large SU peninsula in the very east ^^