Help Needed With Quilting

OK.  This is a shameless plea for advice.  As you may, or may not, be aware, I am working on a cot quilt.  I can finally confirm I have a completed quilt top.  It is my first EVER!  I have nearly finished quilt tops and blocks that are going to be made into quilt tops, but this is the first I have ever finished and it damn near killed me in the process, but lets put that to one side for the moment.

Here is the finished top.

I really love it and I don't want to ruin it now, and here comes the bit where I plead for advice because I really don't know what I'm doing.  I have some cotton batting and it has this on the side of the packet:

For ease and speed I wanted to simply stitch in the ditch along the obvious straight lines of the quilt and inside each "box" of the blocks, but I'm afraid that will leave too much of a space unquilted.  The white part of block on which the elephant stands is approximately 8" x 8".  If I leave this space unquilted will it look weird, or is it bad for the quilt?  I've never done FMQ and I don't know if I have the time or the stamina to learn in the week I have until we visit the recipient.

As I like the crisp look of the squares I plan on pre-shrinking the batting.  The instructions are for a top loading machine.  If I simply leave it to soak in a sink for a while and then get rid of the excess water with a towel will that do the trick, or does it really need a spin in the machine to get rid of the water before leaving to dry?  I'm asking because I don't have have a top loading machine because I live in the UK, where these are rarer than hen's teeth.

Right, on to the next bit.  I have found a piece of fabric that I think might work for the back of the quilt.

This mottled orange and yellow fabric is nice and bright.  I plan to is break up the back with a panel that has the three purple fabrics that have yellow and orange in them, divided with white fabric.  The panel will be bordered by white fabric.  Will this tie it together enough, or should I find another fabric which is more lime or turquoise in colour?  Basically will I get away with using stash fabric or do I have to the shops? I know the baby won't care, but the parents will, not to mention I'm more than a little precious with my very first quilt.

I know there are experienced quilters out there - please help me!!!  I don't want to mess this up after all this work.

If you want to see an actual finished project, click on the buttons below.  I'm only very tenously joining in with my finished top!