It's very... weird. The first ending seems sweet but is very much a bad ending, the second ending is just confusing, the third ending should objectively be sad but is hopeful.
Kind of - it's a weird and very open-ended game but most people agree that the game is about how immortality would be commodified by capitalism and devalue life
No, but there's a target in the Seaside Shock level that mentions having sex with bioslaves who aren't fully in control of their actions as the name implies.
It's low poly but there is gore, headshots decapitate, and powerful weapons (or enough hits to the body) can cause npcs and enemies to explode in chunks, organs from gibbed enemies can also be sold on the black market, there is an option to change the blood color in the options menu.
Cops are depicted as a literal cult, and the head took everything from the seized narcotics and turned into a bouncy castle. So no, cops are not depicted in a sympathetic light.
Definitely don't play this game if you're sensitive to visual stimuli. The visuals are designed to be abrasive and headache-inducing even for people who aren't!
The opening cutscene shows our protagonist in the shower, with a visible butt, no genitalia is shown. In the cruise ship level, some NPCs seem to be naked, I don't think they have nipples or genitalia, hard to tell with this game's artstyle.