1 is ship girls, like from Kantai Collection. I'm not actually sure which ship that is, nor do I care to check, just that multiple groups of people have made anime girls out of ships.
4 is Yuka Takaoka of the 2019 Yandere Stabbing (we have a page on that), because artists art and people like yanderes for some reason. Murder is cool, I guess.
And 5 is Roro-chan, a live streamer that live streamed jumping off a building in 2013. We have a page on her too.

The ship girl is the light cruiser Montpelier from Azur Lane.