google-plus
I thought the circles were listed in alphabetical order, and started prefixing them like "1-Family", "3-Acquaintances", "9-Strangers" but now I added a "5" which is listed last in the circles screen and in dropdown lists.
What's the sorting logic, and can it be influenced?
(Of course this could be a feature they're still working on.)
There doesn't appear to be a one click option to clone a circle but you can do it by following these steps:
View circle in tab
More options > Select All
No, there isn't. I have seen several people post such a proposal as a Google+ message, however. I hope that Google is considering it.
There is at least one guy who is faking it by creating multiple, specially-named circles. For instance, he has a "Friends: Online" circle and a "Friends: All" circle. Anyone he drops into "Friends: Online" he also drops into "Friends: All". This'll break down, of course, if he forgets someone.
Here's a similar approach.
Best Answer
Just announced: You can now manually re-order your Circles.
Announcement on Google+ by a Google Engineer, with video
It's now basically as easy as:
Left to right will appear highest to lowest on the sidebar when viewing your stream and wherever else your circles list appears.