I mostly agree that the author is dead what matters are his intentions there are many inconsistencies, like the ones you pointed out, as well as the stats. Was Misa’s intelligence as low as 3/10? I think not! Was Misa's love pure? And Mikami’s height Is it 182cm or 175cm? and so on...

There is this section on HTR13 in which Light puts Misa in the ‘God Squad’ and in ‘The scoundrels who threaten me!‘ which I personally see as canon this is why I agree with Ohba that the reason Light won't bother saving her is for being a "bad person" and killing innocents..

Yet even without that section I think there might be some evidence for it? though not sure if it makes sense but Light’s behavior towards Misa changes when he loses his memories Yotsuba|Light isn't convinced that Misa killed people Misa continues being just as clingy, annoying, stubborn, reckless, coercive aggressive etc.. As she was before yet he defends her and would have protected her. 1 234 quote: Yotsuba|Light: “i may want him captured, but this is no good." Misa: “why not...?” Yotsuba|Light: ”obviously because it puts you in danger." Misa: “what? You’re worried about me? Yay!” Despite being uncomfortable with her behavior, he dismisses her verbal sexual advances and ignores her without rancor. Meanwhile Kira|light is impatient he wants to kill her, 5 punch her “This is the first time that I actually want to punch a girl…” 6 he barely tolerates her he is forced to protect her “I have to deal with her for the rest of her life? And not only that, but protect her from being caught….“ 7 he wouldn't have bothered with her when she outlived her usefulness he cheats on her doesn't give a damn but evidently he cares about Sayu since he would give the DN in exchange for her life? but Misa does endanger his life when she's Kira but I think we can say for sure that he doesn't hate her for her Yotsuba antics? also remember that HTR13 translations should be taken with a grain of salt like that infamous HTR13 quote? 8