Yes, all true

1) People DON'T realize how much lend-lease support the US and England gave the Soviets (Stalin privately admitted they would've been screwed without that, but of course publicly didn't mention).

2) The strategic support of US/Britain (thanks to Eisenhower/Roosevelt/Churchill) was immense (and questionable). They let the Soviets have Eastern Europe, when they probably should have accepted the late-war deal by German high command to depose the Fascists in return for support in helping push Stalin (the greater enemy, in Eastern European minds) back to Russia.

3) The Russia bravado completely ignores the Pacific Theatre, which we pretty much fought by ourselves. They tried to jump Japan like vultures at the end, ended up with part of Korea.

4) Yes, the Soviets made a tremendous human sacrifice (approx. 10 million military deaths vs around 5 million for the Germans, 2 million for the Japanese, and 400,000 each for the United States and United Kingdom). I suppose one could argue that the US/UK won more with equipment and the Soviets won with manpower, making an effective tandem in Europe.

5) Since Germany and Japan ran out of pilots, many planes and ships by about '43 and were economically isolated, I wonder if they were military "paper tigers" in terms of long-term military might (like Russia today). Back then, the US & Britain had disproportionate industrial power, once they got going, so the question is more like "if the US/Britain had properly understood the Soviet threat at the time, they wouldn't have helped Soviets get a strategic/industrial foothold" (and possibly committed more resources to bottling them up, but that would've also cost many lives)