Are you going us to allow to select which buffs to hide? For example i would be quite happy if i will not be shown the target class buffs and medals.
yes, this speaks to my earlier post about wanting to be able to glance down at the (de)buff bar to check for the presence or absence of something specific.
I think the most general statement of the problem is: Even when there are lots of buffs, I should be able to find whether (de)buff <x> is present or not and how many stack very quickly.
Getting rid of uninteresting buffs is one solution. grouping buffs by types (of some sort) and then putting them in a fixed area is another.
turning off some buffs also frees up screen real estate but I think that is less important than improving the ability to find key information quickly.