@gaigous Romantica is part of the problem; the author's choice of emphasizing the shota-ness is another. One character being a creepy fucko is disgusting but tolerable, the manwha author going out of his/her way to play it up is really pushing it. If it gets to the point where the author is making creepy shota bullshit an integral part of the story, I'm out.
As for hentai-pedo vs ice-cream-truck-pedo, I may be misunderstanding your point so correct me if I am, but I don't understand why you're trying to argue that one is more...admirable? morally acceptable?...than the other. Someone is not a morally/ethically better person just because they lack the drive to inflict their perversions on others. The only difference is whether or not it's necessary for me to use violence against them.
As for Nobunaga FGO, I'm not familiar with the character or anime, but judging from the examples you've given me I would argue that's not loli at all. It doesn't fit the definition I listed below; she has a late pubescent body type, and there's no erotic content or context in those images. Unless the anime she is present in has a lot of ero content I'm unaware of, there's no basis for calling her a loli.
Finally, concerning "useless sacks of cute", the competency of the child in question is irrelevant. I have no issue with artists including children in a story in most capacities; it's the fetishization of them that pisses me off.