Hi beaniedog, A- I dont know if you have any hose pipe restrictions in your area, maybe you can find out from your supplier ? Now that the autumn has arrived, I dont think its so much of a problem as it was in the summer. The moisture in the ground is much more likely to stay there now, so I would'nt be overly concerned, rain butts are filling well in my garden.
B-The worm casts may suggest you have ample moisture in the ground, the worms actually do quite a lot of good work in the garden by airating the soil and turning organic matter into food for plants. You always see more worm casts in the autumn,so its probably just a temporary thing anyway. If they are unsightly you could try brushing the lawn with a Besom broom to desperse them or collect them (the cast make good nutriment for other plants too. You can usually pick up a besom broom pretty cheap once Halloween. Good Luck Tbird+