Omega-3 Improves Your Pet Health

I would consider finding a qualified veterinary homeopath or homeopathic veterinarian for her.
From your description of her symptoms I would suspect there is some underlying chronic disease there and a homeopath is the best practitioner to consult on that. They treat the “whole cat”, choosing the best constitutional remedy for the totality of symptoms and don’t use suppressive drugs to deal with them one at a time.
You can go to: http://www.littlebigcat.com and read Dr. Jean Hovfe’s article titled “Introduction to Homeopathy” to learn more about that medical science.

Here may be some possibilities of whats up:
Vomiting / Regurgitation: Vomiting, characterized by expulsion of bile and / or digested food, is indicative of a problem and should be reported to your veterinarian. Regurgitation, characterized by expulsion of tubular, bile-free undigested food, is often caused by hairball obstruction. While this may not be indicative of a serious illness with your cat, you should consult your veterinarian if this problem persists.
Eye & Ear Disorders: Eye discoloration in senior cats is often a normal part of the aging process. Usually it does not interfere with vision and does not need treatment. Some cats develop cataracts, but they are relatively uncommon. If your pet’s eyes become red and watery, the problem could be conjunctivitis. If this condition persists, consult your veterinarian. Seeing and hearing may diminish with age – one more reason you should not allow your cat to roam out-doors. At home, be patient if he doesn’t always respond to your call, and don’t frighten him by suddenly coming up behind him unannounced.

I’m not a vet and I won’t ever pretent to be one. I have had cats all my life though…So that said, just take what I say with a grain of salt.
Watery eyes-not sure where you live, but cats can have allergies too. Keep kitties eyes clean by washing several times a day with a warm wash cloth. You may consider giving kitty a bit of benedryl and see if maybe she has allergies.
Dark spots and discharge in ear- first of all, clean gunk out daily but also try a drop or two of baby oil after you clean them, massage gently into her ears. This will kill mites as well as moisten ears to prevent dry skin problems.
Not sure if the scabs on the chin are something else, but try putting a little triple antibiotic a few times a day. See if that helps.
If kitty has a cold or virus, she may be fatigued just like your or I would be. Let her sleep. Rest will help her.
Rubbing the sides of her face. This could be her itching where the scabs are healing (healing wounds do itch) or she could be leaving her scent. Cats have glands on the sides of their face.
Vomitting. My older cat has a sensitive stomach and I’ve learned to give her food that is better for her. Look at the ingredients on the bag of food. Chicken-by-product is all the left over pieces of the chicken not used for something else ground up into food. Or corn-meal or rice…last time I checked, my cat was a carnivore…not a chicken…she doesn’t want chicken feed. So I make it a point to feed her food with the primary ingredient being actually meat.
Stooling elsewhere…I agree with previous post…usually behavioral OR she is too ill to get to her litter box.
Hope this helps.