Your comments

Worth a shot, but no.
Stock iPad Mini 16GB now running iOS 6.1.2
I hadn't rebooted, but have just installed the latest iOS update. On first attempt since, the scroll issue appeared resolved but the cursor pad did not come up on first 2 finger tap. Split and Merged the keyboard and then the cursor pad would appear on 2ftap.
However... After sleep and wake, it exhibits all the same bad behaviour. :-?
With the keyboard split, I can see the cursor pad appear behind the keyboard. Hiding the keyboard and tapping to place cursor and redisplay the keyboard fixes the issue. All pop-ups, cursor pad and scroll all working fine... until next sleep/wake cycle. :-?
At least I found a way to make it work, but not very clean. Maybe it's just this iPad Mini. I'll keep you apprised. Thanks for the help.

I do know how to access the cursor pad, and it works fine for me on the iPad, but not so much on the iPad Mini. It occurred to me that it may be behind the keyboard, related to the text editing issue. 

Yes I can scroll to the last several lines, but they snap back behind the keyboard. 

The 'files' pop-up also extends below the top of the keyboard (unlike the expected behaviour I see on the iPad) requiring me to close the keyboard to access the file tools. 

This does appear to be only an iPad Mini issue.