As you can tell by my username... i like go a bit funny when it comes to chooks :O
Don't worry about the chooks if they are old and dont lay much... you can still teach them to learn to work for you and you can always buy younger chooks as well. If you've only just moved them to you property they can go off the lay a bit.. this can be anywhere from one to eight weeks!
A couple of Q's about them.... were they battery hens? or if they arent, do you know whether they just lived in a pen? Do they eat scraps or were they raised only on grain?
I ask b/c my first chooks were ex-battery and took a long time to get them out free ranging for their own food as well as teaching them to eat fruit and vegies(not much luck with the vegies yet but the younger ones love em) and to cut back on the grain. If you can it's best to get your chooks to eat greens in the morning and a bit of grain in the evening to balance their diet.... plus its easier to get them back in the pen with grain
With the sheep... i am not even a novice but i did read an article on organic sheep farmers using copper sulphate in their diet to control worms and other parasites(get professional advice on this). I also know a biodynamic farmer who uses Guinea Fowl to run with his cattle and he said he only has to treat his cattle for worms only once or twice a year compared to his neighbours who have to treat theirs from 12-24 times a year.... a huge difference.
You have asked a lot of Q's here that would take a while to answer and i wont pretend to be able to answer them for you. There are some fantastic books on ducks and poultry out there written by ppl who know what they are talking about. Plus it would take a long winded response from me and far be it for me to ever do that on this forum :p
Good luck and let us know how you get on with the 'good life'
Township of Boonah (pop 3,000)
2.7 acres of gently sloping volcanic soil
"Progress is a spiral; the pendulum swings back as well as forward. The new postindustrial world, for which many of us are striving, will see an ecological renaissance".... Rober Hart