I don't have a ds4 controller so I can only relay to you what I hear from everyone else. The controllers do work fine, but if you choose to use them, you have quite a bit of setup to do.
[list type=decimal]
[*]Install and set up DS4Windows. Looks like this allows your DS4 to be emulated like an Xbox controller.
http://ds4windows.com/
[*]Click your start button and type "Set up USB Game Controllers" in the search box. Click it.
[*]Select your controller from the list, click "Advanced" then make sure the correct controller is set as your preferred device in the drop down box. Click OK twice.
[*]Since FF7 has limited controller support, if you want full support, you need to trick the game by mapping keyboard keys to your controller using a 3rd party tool.
[*]I'm told AntiMicro works well. Download and install that from here
https://github.com/AntiMicro/antimicro
[*]Run AntiMicro (or whatever your preferred controller mapping tool is)
***AS ADMIN***. Configure AntiMicro/your preferred tool to map the keyboard keys you want to your controller.
[*]7th Heaven 2.0 includes controller button "presets". These simply change your keys and buttons inside of FF7 as if you opened the game and went to Menu>Config>Controller. 7H is not a mapping tool.
[*]If you don't want to use a preset, configure your own controls inside of the game, go to 7H>Settings>Game Launcher>Controls and click the Save (floppy disk) icon.
[*]Make sure those same controls are set up in your AntiMicro.
[*]Ensure your controller is fully on/plugged in/connected first. Then launch FF7.
[/list]
If you're getting double-input in the game, this little piece is from the DS4Windows site:
- I'm getting double input/ Weird input in some games, how do I fix it?
That's because the game tries to (though usually badly) support the DS4 on it's own. You can solve this by enabling Hide DS4 Controller in DS4Windows' settings, then connect the controller BEFORE you launch the game.
That's the most comprehensive post I can possibly do. Anything beyond that, call a priest, a voodoo doctor, I don't know what. Or buy an Xbox controller for crying out loud.