Missing input settings

I'm working on hooking up GNOME's input settings to Wayfire via gde-gnome-dbus, and this has revealed some missing functionality in Wayfire's input settings. Whenever I refer to g-c-c I mean the GUI Settings app in GDE (gnome-control-center). Various preexisting components of the OS like g-c-c, gnome-settings-daemon, and even gtk itself will use the GNOME input settings and expect them to reflect the hardware. Here's the missing features:

• There is no way to swap the primary mouse button (left-handed mode). This can be global for mouse/touchpad.
• There's no way to configure the maximum delay to register a double click. Is this even handled in Wayfire or is it toolkit-specific?
• It is unclear if natural-scroll controls the mouse, touchpad, or both. In any case, ideally Wayfire would have separate touchpad-natural-scroll and a mouse-natural-scroll settings. g-c-c has separate toggles for mouse and touchpad natural scrolling
• Same as natural-scroll, but for middle-emulation. Some cursed mice do not have a middle click. Ideally middle-emulation would become touchpad-middle-emualtion & mouse-middle-emulation
• Currently, in wf you can only enable one scroll type at a time (two-finger, edge, etc). g-c-c allows you to turn both types of scrolling on simultaneously.
• Currently, there is no way to explicitly disable all touchpad input. Some laptops have a button on the keyboard to disable the touchpad that GDE needs to handle. g-c-c also has a switch that does the same. I'm envisioning a boolean setting in the [input] section called touchpad-enabled that enables/disables the touchpad

Start with the linked src/wf-gsettings.vala integration and inspect Wayfire's existing [input] settings and their handling. Compare the current settings with the GNOME input settings described here, then determine the scope for separate mouse and touchpad controls, simultaneous scroll modes, and touchpad enablement. Done means the supported settings reflect the relevant hardware and GNOME controls.