First of all, thank you for adopting Eva! It's sounds like you are doing a great job caring for her. Cockatoos are challenging, it can be a little overwhelming at first. Research certainly has it's place but no matter how many written volumes you read through, there's nothing like hands on experience.
Two things that will work in your favor are Eva's age and simply time. Cockatoos move a little slower than other species. Try to relax, Eva will follow your lead, Toos are very tuned in to their caregivers. Rotating toys is very beneficial, toys should be checked often for damage so they don't become a safety issue. Parrots sometimes need a little practice to fully appreciate a toy. Rather than automatically rotating them, I would leave the toys in the same place long enough for Eva to discover them in her own time. You'll know when Eva chooses a favorite by the pile of debri on the floor.
Keep working on her diet, at ten months she should be more willing to try new foods than she will be later. Toos love sharing food, sometimes seeing a favorite human enjoy a healthy snack makes all the difference. Keep offering veggies, sliced, diced, chopped, shredded, steamed, baked. Add cooked beans, pasta, sprouts, cooked grains, cooked chicken or fish in moderation, the list is long. Stay away from avacados, always check your safe and toxic food list before offering a food for the first time. Until the list is imprinted in your mental file, it's helpful to keep the list on your phone while shopping.
Toos are powder birds and more prone to plucking than various other species, that's no reason for undue paranoia. Toos have huge feather shafts that become sore, itchy and annoying while they are growing in, its normal for them to preen these feathers, sometimes it may look obsessive when it really isn't. Dry air in the winter is another reason for itchy skin. A cool mist humidifier really helps. An air purifier is also beneficial around any powder bird. Keeping the dust to a minimum will help keep your Too's skin healthy. Adding a little oil to the diet will help too. Tree nuts or a little coconut oil added to the diet is good for skin and feather condition.
Toos are awesome birds, remember to have fun.