#1 problem set you can overcome that easily enough with clever writing
#2 Sample size millions a whole country maybe you could narrow it down to a village
#3 availability the target is dead do you do personality analysis on their french memoirs
#4 hypothesis dependent on hypothesis that modern society(values culture beliefs behaviors and attitudes) was directly and moreso by this than michael jackson shaped by loss shaky foundation
#5 Type A's probably survived the great wars better due to attention to detail and hygiene and obsession with control than Type b,c,d, f,g Since field san and such were the greatest killers.

Just seems in the very hard to do block.

You could always just write it as an editorial for the Times and not have to back up any of your claims with research