I don't think the interface is terrible. There are two controls, maybe three, that need a serious update. All this ignores hotkeys, of course.

First, the camera controls. That really has to be updated. Does anyone actually use that little face in the middle to select a camera?  And the little white buttons you have to hover over to see what they do isn't intuitive in the least. Those two raised palms aren't obvious either. The trackball and the pointing fingers for left-right/in-out are okay and I use all the time, but the rest? Yeesh. Otherwise, I use Netherworks camera control panel to select and modify the camera settings. So the obvious solution, at least to me, is to merge the two: keep the trackball and the left/right/up/down/in/out control (perhaps updating them), replace the camera select with either a button panel or a menu dropdown, and right click and flyout menus off the selected camera (as used by Netherworks) for the camera options.

Second obvious one is the light controls. There's probably as many opinions on how to update that as there are people, but there are obvious shortcomings. The lighted globe is, again, not terrible in that it allows you to quickly adjust lights and where they are pointing, but there are obvious shortcomings.

1. There's no differentiation between types of lights. If you click on one of them, unless that light source happens to be in the field of view or you look at the parameters, you can't tell if it's a spot, a point light, an IBL, or an infinite light.

2. If you have a bunch of lights with the same orientation (say a row of spotlights on the ceiling of an interior scene), they'll overlap and you can't select a specific one from the light control, but have to select the one you want from one of the menus. If there's a bunch of lights close together, it's still unnecessarily difficult to get the one you want.

I'd say drop the thing entirely. Really, the only thing's it's good for is infinite lights. IBL controls using it are pointless, it can't be used to place point lights (and having an "orientation" on a point light is a stupid concept anyway), and its controls are nearly useless for spot lights.

A replacement could be a light panel consisting of four buttons (infinite/spot/point/IBL). If no light of a given type is present, the label is grayed out or whatever to indicate it. To select or add a light of a given type, click the button that opens a flyout menu where you can add, delete, select, or modify lights of that given type.

The third control I'm "Enh" on is the Dots. Not terrible, but someone can probably come up with something that works better.