I don't think there are codes for these features. But I think the first one community can implement it.

I took a look at the source code, it should be in components/Dashboard.qml. The speed and distance blocks are wrapped under AssistanceItem {}. We have speed and distance variables available so distance/speed + some decoration to beautify the output and alas we have the minutes left to destination. However, I think in GPS they do something extra to avoid erratic jumping of the value, for example smooth the speed over a certain period. Any idea on how to do the smoothing?

Traffic re-route might be tricky, I haven't looked deeper but I would think we need get info from traffic and routing models to know there is traffic event along the original route. Unless there are some ready-to-use signals to trigger re-route event....