We looked into it a bit. Shouldn't be that hard to implement, but it's not very high on our to-do list, sorry.
https://github.com/Ultimaker/Cura/blob/2.1/resources/machines/ultimaker2plus.json
It's there, but you need to manualy modifiy the theme file.
Already implemented. Try shift + arrows and + & - for zoom.
Yes it does. But you are on a mac. They put the wrong label on their backspace button (they say its a delete button, but it isn't.) Use fn + delete.
This works on the nightly.
There are rulers; the squares on the buildplate are 1cm. The scale tool also gives dimensions.
Standard? Metric is the standard I did make a barbarian to standard conversion plugin. you can find it on https://github.com/nallath/BarbarianPlugin.
Thanks!