When you click to add a new game object, a dialogue opens that is focused. Without clicking anything, you can simply type the type of object you want to add and hit enter. This is fast and should be the model for how other dialogues behave.
This contrasts with adding behaviors and variables to an object, which don't follow the same flow. After clicking either of those you have to then click into the new popup window. The dialogue should already have a button that is autofocused so you can just hit enter, type in the of the behavior and enter, but it doesn't.
Instead, you have to use the mouse longer than is needed, click more than is needed, and travel the length of the screen. This makes creating objects and adding needing behaviors tedious for no reason.