Nef

Bizzare video output - it is present only after full shutdown and unplug from wall

Yes, try yourself.

Yes

You definately should not. The not used memory is simply wasted. When other service needs memory it will gain it. In the meantime, ARC will provide you instant access to most common used files and most recent ones. You really should not be worried by this memory consumption. On the contrary, with ZFS you should buy more RAM to make ARC as large as possible.

The chosen Milestone is wrong - it should be "Next release".

Added monitoring of L2ARC in graphs