Otto question: did he purposefully make the vr version of himself in cherry blossom recall/ae invasion exaggeratedly vapid and heartless because that’s what he thinks about himself?
Otto has an EXTREMELY LOW opinion of himself, so I wouldn't be surprised if this was the case.
His family, when he was a child, kept telling him that he was frail, worthless, not good enough.
Kallen arrived and praised his inventor side, so that shifted to: "I have worth for her only if I do something extraordinary", like CURING THE DAMN PLAGUE. He single-handedly cured the plague and never even recognised this for himself. He saved THOUSANDS but he doesn't even acknowledge it.
Then Kallen abandoned him (and this was a fatal error for her and she was extremely selfish and ignorant, because what do you mean you want to save people, save everyone, but you can't be bothered to recognise that the one needing to be saved the most was your best friend, right in front of you, from his horrible family? Makes her Kaslana Oath feel very superficial)
And since then Otto never really recovered. Kallen went and came back, died, and he spent the following five centuries pretty much alone, because aside from trying to find a way to revive Kallen and developing the Valkyrie system, both from a chemical/organic level and a society one, we don't know much of what her did, or who he interacted with.
From what we know, aside from Fu Hua whose relationship was a lot on the do ut des side, his first real relationship was with Theresa.
And even Theresa, albeit unconsciously, placed certain expectations on him. He's only worth if he protects the world.
So yeah, Otto doesn't have a high self esteem at all, and doesn't place value on his own life.
(Huge error, because I value his life A LOT)