Numbers 5 and 7 have incorrect answers. both answers should be Sherman. The Sherman was the only tank to serve in all theaters - Russia, Pacific, Desert, and Europe. There were 49,400 Sherman's produced, just 400 shy of the total number of all German tanks made. Also, unless you can find a better reference, the answer to number 13 should be Stalin.
Number 7 is extremely incorrect. The production of both the Sherman and T-34 far outstripped that of the StuG 3. Perhaps you meant "what was the most produced German AFV of the war?"
The T-34 is the most produced tank with a total of 80000 units being built
2. Stug 3 numbers still would be less than t-34's of the Ussr and the shermans of USA