One thing I notice about all your suggestions is their covers have anime girls plastered all over them.
Almost all VNs are either character or romance focused (most of the examples I gave aren't, but almost all have it), and featuring the heroines on the cover tends to sell (note how Steins;Gate, FS/n, Phantom of Inferno, http://vndb.org/v382=generic example no.16, Umineko, Higurashi have anime girls on the cover - all those have anime adaptations, go ahead and watch them). If you're trying to say this means they're porn you're thicker than a brick.
Right, it's about whether or not people die if they are killed.
One thing I notice about all your suggestions is their covers have anime girls plastered all over them.