golden chyld - I think getting those squares to work right would require a couple of additional lines of code - we only ever got enclosed characters working with English and we disabled that before the first beta because we had a better way to do the same thing - but we'll experiment with it a bit for 3.0.1.
On register labels: this one we need more feedback on - to me the gray is dark enough that it doesn't remove it from notice but simply makes it easy to tell that it's distinct from the definition which follows, though I suppose that semibold + small caps might be enough to do that on its own.
On variants: this is actually quite intentional - in the vast majority of cases, when somebody looks up a character they want to know what it means, so when somebody taps on 凈 the most sensible thing to take them to is a definition for 凈 rather than a link to a separate screen with that definition.
If we get a lot of complaints about this we could consider adding an option to show /ed variants in the popup, so you'd be able to get the information you're looking for that way, but we're pretty well committed to the idea of getting rid of definitions that simply constitute links to other definitions - frankly it's the only way to keep merged searches from getting incredibly confusing / annoying.
The change we made for Japanese variants was a temporary fix to get around the fact that we were losing information - ultimately we'd like to handle that differently too, probably by use of some sort of dictionary-specific notation to deal with whatever specific types of variants it identifies (e.g. a Japanese variant in CC would get a little superscripted J next to it, in the "HZ" line that appears at the top of the CC entry).
sobriaebritas - that's an option in all dictionaries now, though the beta-testers are still using old versions of a few of them which don't have the Pinyin tagged correctly to allow us to hide it.