Thanks guys. So far, pretty much everything fits. I double checked the height for IG-88 before I ordered it. The columns on the left and right edge are slightly wider than the others for the extra wide figures. The biggest problems have been getting the Kubricks with lightsabers in place so that they could fit reasonably well. As far as non-SW Kubes, the Green Goblin's hover glider does fit so he's displayed without them.
I used Museum Gel product to stick all the Kubricks down on the acrylic floors. They seem to be quite stable. As could be expected, some of the Kubes are loose and their waists are wobbly and some have the over springly legs and they get positioned kind of funny.
However, when its all said and done, I'm really happy. Its nice to see what a few months of hard work can turn into