To expand any perspective properties it requires clicking the small little arrow to the left of the key, however it would be great if you could just expand it as well by clicking on the key.

I think there is a slight potential for a conflict here between "click to expand" and "double click to rename". However if I had to guess I would say there is much more expanding/collapsing happen than there is renaming. So it would likely be a slight inconvenience to watch your prop open and close quickly on a double click.

The arrays don't even do any thing on click or double click