It would be good if windows/dialogs could remember their size/position.
Most of the times I would be focusing on Plug only so I wouldn't mind if it takes the whole screen. I would set my main (amp) window to take up the whole upper half of the screen, with bottom half divided between effects dialogs. I wouldn't mind if effect dialogs open up even when the effect is turned off.
In amp window, I would set the load preset dropdown (I know, this bit is yet to come) with quite big font, then amp name a bit smaller but still bigger then the rest.
Same for effects, the effect name should be prominent with somewhat bigger font (same size as amp name)
(Did I mention that I have special interest in usability/UI ;-))