While working on my level I want to keep things tidy and organized. As a Blender user, I am used to locking (restricting the selection) folders or a specific object. Locking folders is in this case in the world outliner. This, of course, prevents selecting it and is useful when matching a level blockout.
The last thing is a bit silly but worth mentioning, I hide a lot of my objects to experiment with the final assets. So when I quit Unreal and start it the next day all of my objects are visible again. Working with small scenes is not a problem, but it is a nuisance when I need to hide the objects over and over.
Please take these little features into consideration, it would speed things just a bit.