What about avoiding to bloat the UI with fast refreshing rate data that will only slow it down and will only be of interest to a handful of users ?... FYI, the status bar refresh rate was voluntarily capped at one refresh every 0.2s (against once every frame in the original Snowglobe code) to gain speed.
I don't use voice at all, so I'm afraid this would be a very low priority feature, not to mention that sorting by distance avatars in a list is also something that eats up a lot of precious CPU cycles (the original radar implementation, that was taken from Dale Glass' viewer was especially costly in term of CPU power and badly impacted the FPS rate: I had to optimize the code and slow down the refresh rate to something reasonable, and it is yet still not as fast I would like)...
Feature requests that have not been replied are simply on the "might do" list (i.e. I didn't yet take a decision, mainly because higher priority stuff is in the pipeline).
Text highlighting in chat and group IMs on avatar name (legacy and display name) or nickname occurrence is already there ("Peferences" floater -> "Cool features" tab -> "Chat, IM & Text" sub-tab).