Also, if anyone is using a RAD for developing the software for a customer, never, ever, ever, show the customer that a button or any other widget can be easily shown or not, moved, resized etc. on the panel, or be prepared to be asked a layout change like twice a day, of course for free since it's just 5 seconds of clicking. Seriously, sometimes it's much better for users to believe that the UI is some sort of black magic that cannot be touched otherwise they'll waste all your time rearranging the layout instead of concentrating on more important issues they're not aware of.
(0) Some good research has been done in the past about how much information the user can be shown before the amount of it ends up distracting from the problem; iirc probably IBM was involved; I was told about that in the mid-end 90s but it likely dates from the previous decade.