Feeding the cat dry food exclusively contributes to kidney stones, I at least recommend varying between dry & canned.
That's only partially true. Actually both dry and canned cat food can cause kidney stones, and feeding a cat an exclusive dry diet will not increase kidney stones. It really depends on what food you feed your cat. If you're buying your food at the grocery store, any food there is relataively high in ash, and can cause kidney stones in cats, regardless of wet vs dry amounts. If you're buying a very high quality dry cat food, you can feed that to your cat exclusively and have no problems with kidney stones. My one cat that was fed a mixture of dry and wet food, was the one who developed kidney stones. The others who were on a exclusive dry diet of high quality cat food (Science Diet) never developed one kidney stone. Most cat breeders feed their cats an exclusive diet of high quality dry food, since it's the easiest to feed multiple cats. My cat breeder used to feed all her cats a high quality kitten food, regardless of age, since it was the lowest in ash content. Now, she uses a all-natural holistic diet, which I also now feed my cat. It is very expensice $40 for an 18 lb bag, but it's the best food for my cat.
Now, back to the OP's question. The items you mentioned are just about right, with the exception of treats. Cats aren't trained like dogs, and rewarding them for good behavior doesn't reep the same results as does a dog. A kitten that is 10 weeks old, should already know how to use a litter box and scratching post if coming from a proper home, they learn these traits from their mother. If not, your friend will have to litter train, and scratch post train. She will need to buy the cat repellent spray to discourage the cat where not to scratch. Also, if the cat isn't litter trained, she also will need to buy the urine removal spray. It's different than using a carpet cleaning solution, which you hav eto use anyway to clean up an accident. Cats like to go in corners, as well as their litterbox. If the cat isnt' trained, and all you do to clean up an accident is clean it, the cat will still smell the accident, and re-use the spot, reinforcing the behavior to go there. If you clean it up and then spray it with the urine removal spray, the smell is then erased for the cat, and they won't go there again out of habit. As for a litterbox, if your friends works and isn't home often to clean out the box (it needs to be done at least daily) have her buy a Littermaid. It is a self cleaning box, that scoops out the box everytime after the cat uses it. It is really convient, especially if you plan to travel and leave the cat at home. We usually have to change the plastic recepticle once a week, so it's very convient for busy people.