The interact hot key became insufficient after vehicles were added.
Up to the addition of vehicles I think the interact hot key was fine. But now that we have vehicles with multiple seats and a trunk I think it would be helpful to have separate hotkeys for entering/exiting a vehicle as well as opening/closing their doors. This would make the end user experience more consistent.
Why? It boils down to this. The key I use to open/close things everywhere else in the game, has an entirely different effect when faced with a vehicle door. If I want to open/close a Building door, window, vehicle hood, or vehicle trunk I hit the interact key and it opens or closes. But faced with a vehicle door, now the result is entirely different. Instead of opening the door to give access to the storage space within, I enter the vehicle. Worse, if there are things on the seat, the character first has to move them to another seat. Fouling up attempts to organize OR preventing immediate access to a seat when actually trying to enter the vehicle.
With a couple of extra dedicated hotkeys you can make behavior more consistent through out the game and therefore more intuitive and by extension less prone to frustration (A.K.A. executing the same gameplay action via entirely different UI actions).
So what I would consider doing;
Enter/Exit hotkey
Enter or exit a vehicle.
Go through a window.
Toggle hotkey
Open/Close window/hood
Open/Close door/trunk provided you have the key or it is unlocked (building or vehicle)
Turn on/off light switch, lamp, generator, tv, radio, washing machine, dryer, oven, microwave, stove, etc.
Interact hotkey (For conditional or context specific actions)
Lock/Unlock object provided you have a key and it has a lock (Building or Vehicle or padlock secured object)
Open/close curtain (because you don't want to confuse this for opening/closing the window, and it only applies to windows with curtains)
Break window (if closed and unbroken)
Clear window of broken glass. (if broken)
Connect a generator/battery charger (which is why on/off is controlled by the Toggle hotkey)
Climb rope (all though this might be better under enter/exit, can't remember if you can climb up or down dynamically or if you just climb all the way up or all the way down without further interaction, key holding, etc.).