What if someone bought a PS4 game disk for Horizon zero dawn, could it be installed on a PC (no remote ps4 involved) and no imulaters?

Sorry, no.

It may contain a lot of similar data, however executables and data on disc isn't quite the same. Mostly OS differences.

In watching several different video walkthroughs, most of them on a PS4, they're not all the same as my GOG PC version.

If you check the Horizon Zero Dawn forum page his has a bunch of threads complaining about the game even calling it a shooter.

Indeed. Console ports most likely would have lower polygon versions of characters, monsters, probably identical music, and anythign they needed to cut either hardware/ram limitations (so some quests or features, fewer enemies/objects spawned/acting at the same time) or graphical or other. Though i would expect the PS4 to be 90% (other than resolution and/or lighting and framerate) of the PC version.

I'd love to try Horizon Dawn.

Sadly no, but it would very cool if that was possible.

Also can we just stop downvoting people for ASKING QUESTIONS?!

PS4 is like the original Xbox, and runs on x86 hardware... meaning with the right environment (similar to WINE) that would forward the appropriate calls, one COULD emulate the PS4. However if there is one coming out I'm not aware.

Unlike the PS3 which uses a different processor type that's very difficult to emulate those seem unlikely to get any attention for many years yet...

It will be a while before we see a PS4 emulator.

I agree. If they get it most likely the original Xbox one won't be far behind.

There is already a PS4 emulator.