Incredible. Thank you both Soquili and Charles. That is some support! I had tried intersect shapes; holding down the minus key was the missing link. Now that I know about it, I see it is mentioned in the line at the bottom of the window, I'd missed that before.

It's a bit of a stretch though to hold down both shift and minus to resize around the center .

FWIW, I'm now happy as a clam and have just paid my $79 + shipping with two days left on my demo. Since using Xara Xtreme won't be something I do every day (well, it would if I had the time, it's truly a pleasure to use), I probably won't be seen around here too much in the near future.