Does anyone have a suggestion on how to hide the "weight" and "gold" cost (and maybe name altogether) when you highlight an item while walking around? I don't want to see it all all. Ideally, I'd like the gold value to ONLY show in the barter menu? Is there a way to do this? If it's impossible, I don't want to waste my time trying to mod it.

You'll need to either edit xml files themselves or use OBSE UI functions to modify them dynamically.

It should be doable, but requires knowledge of Oblivion's xml files structure.