View settings can be seen in the top-right of the editor.
Using the Zoom slider you can zoom your view in and out. Disabling the Extended Zoom setting will lock the Zoom to a maximum of 1/3 in-game scale to prevent pixelation caused by asset scaling. Zooming via slider will use the center of the screen as a focus point.
The Grid Overlay is useful if you're trying to line up various Stuff. The slider will determine the opacity of the Grid Overlay. Anytime the slider is changed to a value other than 0 (all the way to the left), the new opacity will be saved for toggling via the Toggle button.
Rotation Snapping is useful when you want various Stuff to have specific degrees of rotation. This slider snaps to values of 15°. When a non-zero value is set, rotating Stuff will occur in steps of the set degrees.
Clicking on the Center Rooms button will move and zoom the editor to fit all rooms in your window, if possible. If your map, fully zoomed out, is larger than your window, it will zoom all the way out and center it.