Mike, we did our first house swap this summer and all went well. I've always wanted to do one of these, however, my husband was quite indifferent about the idea. He agreed to do one after I asked a friend who had moved home from from southern England if she had any friends who might want to do one.
As she put it, I have no problem with recommending either of you to each other. The other couple and us made arrangements early on for extra auto insurance on one vehicle each with the paperwork in the glove box. Luckily neither of us had any accidents. In addition, we had our vehicle tuned and serviced. I had also notified my homeowner's insurance company that these people would be in our home so that everything would be up front. Our agent was glad that someone would be in our home while we were away.
I left a detailed booklet of how to operate our appliances and instructions, along with a copy taped to the main appliances, for our home along with repairmen's phone numbers. None of this was needed.
I cleaned out our refrigerator/freezer so that the other couple and their two daughters had plenty of storage space. In addition, I left vacant space in closets and drawers.
Be prepared if you should do an auto swap in England that you will probably get a vehicle that not only do you drive on the left side of the road but you will also shift with your left hand while sitting on the right. Plus, you will be driving on narrow lanes on the left side. It is doable but you have to be on your toes and especially when you enter circles. You might prefer renting an automatic. Of course on the mainland of Europe you won't have such a problem.
We spent the night previous to them leaving in a bed and breakfast close by so that we could meet. I believe that made them feel comfortable with us taking over their house for two weeks.
It was a wonderful experience actually living in their home and learning of the differences of the two countries.