I don't know how many buttons FFXIV supports. I only have a 5 button razer mouse. So if you have 15+ buttons and they all work great for you. If not just use Ctrl and shift with mouse button 5 and 4.

I also moved my party frame window close to my action bars. So I can have it closer to the middle of my screen to click on them as well as other targets.

This has been working great for me. Its almost like having a addon but its not.