With image in 8-bit you would be able to access 100% of Photoshop Elements features and tools while editing but with 16 bit the editing is limited and also usage of layers.
Elements does not support 16 bits for layers nor for local and detail adjustment tools.
Elements supports practically all 16-bits editing for global adjustments and in many filters.
So, if you want to take advantage of high quality tif, psd or raw files, the obvious workflow is to stay in 16-bits (normal editor or Camera Raw editor) for all global edits. That's where 16-bits make sense by avoiding posterization risks. You switch to 8-bits (File >> mode) when you are ready for local or detail adjustments.