On the subject of the red quilt--isn't that funny--I also tried quilt as you go with a large piece, and ran into the same problem.  I made blocks for the central panel of the big church quilt.  It hangs badly.  I resolved to sew the whole thing on a backing--one of these days.

I love the Plum Tree.  To me, it has a very formal look.  I guess it's the leaded glass effect of the black.