Natural things such as nuts will not effect you kidneys. You have to watch out for the non-organic items, such as the chemical added to your food. If you look at a label, can you really name all those ingredients and what they are for. There has been poof that food items will hurt you kidneys, cause cancer, diseases, and disorders- the man-made kind. So watch out what you eat. I suggest you read some good books such as "Natural Cures", "The supersizing of America", and "Fast Food Nation". These are great books to learn about this kind of thing. Or you can search on the internet.
I think eating in moderation will give you the least chance of kidney failure. That said, I personally consume a good deal of nuts and seeds (1 cup of peanuts, 1/2 cup flax seeds, 1/4 cup of walnuts, 1/4 cup almonds, 1/4 cup sunflower seeds) everyday. I've actually lost a few pounds since I've been eating mostly raw fruits, vegetables, whole grains (lots of oatmeal!), nuts and seeds.
From my experience, consuming nuts and seeds tend to fill me up fast, so I don't have to worry about overeating. In addition to their many health benefits (lowers cholesterol, high in fiber, high in certain vitamins and minerals), there have been studies that have shown that individuals who consume diets high in unsaturated fats and low in calories lose weight more effectively than those on a higher complex carbohydrate diet (one such study: November 2003 issue of the International Journal of Obesity and Related Metabolic Disorders that included 65 overweight and obese adults).
Long story short, so long as you eat your fruits and veggies-by all means-consume nuts and seeds; your body will thank you for it!