A god of death is usually peaceful and doesn't create death, they have to provide solace to those who have have to cope with the reality that they just lost everything they have lived for, forever. With this information, Totoro would be the opposite of bloodthirsty, and be extremely passive and compassionate, running…

You know, I don't think that this theory is supposed to make Totoro out as a "bloodthirsty monster of death" - more like an omen of death, if anything (that said, as the creators have outright shot it down, I'd say that it's highly unlikely that it's actually true)