[Feature Request] better mouse/UI control scheme, more configurability

this one is a bit vague, and some people might not agree because it's not exactly vanilla, but anyway, any extra config options that would bring the UI/mouse functionality closer to what SS2 has would be very welcome by a lot of people, so no harm in requesting, imho.

ex. fire with the left mouse button and use world objects with the right mouse button, auto-pickup world objects/frob switches with one mouseclick, looting containers by opening them and then just one-clicking to pick the loot (and then auto-enabling mouselook once the container is closed/the player clicks into the world window) etc.