In the Product Structur Explorer there is an action to replace a component with another or a new component while keeping all the usage link attributes. This is not existing in Product Structure Browser and would be quite helpful. The user experience could be even more improved if the inline search could also be used in a similar way. So doubleclicking the number of an existing component in the uses tab would allow to start an inline search.
The existing functionality for mass replacements within the change task is of course a similar and very helpful thing if your task is replacing objects in multiple existing structures. However, in cases in which you do not use change management - like in the early development starting from a copied structure - this functionality would allow to efficiently derive new stuctures from existing ones.