First of all Welcome to the QB from SE Michigan! We have a number of folks for the UK. Your quilt is so beautiful I love the colors and your quilting is beautiful too.
As far as washing your quilt I always wash my quilts to get any residues out of it from either spray basting or from glue basting which are my prefered methods of basting a quilt. I also prefer to hang a quilt outdoors to dry because I love the fresh smell of drying a quilt outside. It can be dried in a dryer too. I always use a gentler cycle for washing though and let it ring out normally. Color catchers are great when washing for the first time (at least) and using a cold water wash. Again I look forward to seeing you here on the QB. Welcome aboard!!