That's a pretty good first attempt. I agree with above comments about the length of notice to terminate the agreement - I was thinking two or three week's notice. Will the homeowner want notice of your intention to visit? If there's a family event happening, with kids running around, a beekeeper turning up and taking a hive apart would not be welcome!
Only stating one hive is the subject of the agreement will, as JMB pointed out, be restrictive if you need to split or do an artificial swarm so you need to think of some wording to cover this. Alternatively, you could do a vertical separation using a split board for swarm control and end up with one hive that's 6 foot high!
One other thing that springs to mind - I recall from my days dealing with construction contracts that the essential elements of a contract are an offer, an acceptance and a consideration. Your agreement currently has no consideration. I'd be inclined to go for a peppercorn rent of £1 a year paid by the beekeeper "if requested by the homeowner". This does not preclude you giving some jars of honey if you have a good year and the homeowner has been particularly helpful.
Good luck with your apiary agreement
CVB