With the space of a night to get over all my horrible mistakes, the back really didn't look bad except for the two glaring mistakes.
Handed the quilt off to the guild today. They were far less critical of the quilting than I am. One of the ladies, who I know does terrific work, said, "I'd just leave it like it is." I couldn't believe my own ears.
One of the other ladies really saw my distress and said, "We can fix that and it'll look fine." Poor thing didn't understand that she was 'we' and she had volunteered! So I handed her the thread that I brought with me and she started picking the bad stuff out - not entire rows which is what I thought it needed.
So I still like my guild. And hate the quilt.
Thank you all for your sympathy. It helped.