Thank you so much for your kind words, support and suggestions. It really helped calm me down.
I will ring the owner of the quilt store - not to complain, but just to let her know so that she can warn/prepare other purchasers. This fabric does need extra care before use.
A few people have seen the quilt "in the flesh", and they say that they don't notice until it is pointed out. It just stands out and shouts to me.
I treated and washed this item so much that it has got fluffy bits/bobbles on it. I'll have to remove those. The treatments have also reduced the color intensity of all fabrics used. Even the cream isn't the same. It looks like it's be used for years. Not quite the antique look I was going for :)
In future I will use a neutral backing. If anything is going to bleed (which I will do everything I can to prevent BEFORE making the quilt top) - then hopefully it will bleed onto the back.