My opinion for whatever it is, or isn't worth... you are playing with fire. Sounds like Tiki is possibly a jekyll/hyde personality and they are the most dangerous. They can be fine, and turn without warning. The good behavior lulls you in to a false sense of security and about the time you let your guard down, someone is going to get hurt.
No way would I be taking a dog like this in to a nursing home.
Making excuses for his bad behaviors isn't helping the dog or the people he is exposed to. Your mother having a cup or shoe in her hand or the fact that she had a robe on is no excuse for the dog going into an aggressive behavior.
My very first rescue dog was like this. Everyone I talked to told me how dangerous they were. I was going to euthanize her, but my DH said, Oh, she's cute. Let's give her a chance. We gave her a home for over 12 years. I kept her away from people, gated in another room if we had company. She lived out her life safely with us, but we could never relax and let our guard down. I learned a huge lesson. Do I regret giving her a chance? No. Would I do it again? No way.
I wish you luck, as each dog deserves a chance for a good life. However, if the behaviors aren't addressed, it's not a dog suitable to be taking to CG's or nursing homes. It's a lawsuit waiting to happen.
I hope I don't make you angry with my comments -- I know how difficult the whole scenario is. Been there and done it. It's a real emotional issue when trying to save a dog that might not be able to adjust to a normal life.
I know your intentions are good, but you have to consider how you'd feel if the dog ripped a kid's face up or seriously injured an elderly person -- or anyone else for that matter.
I do wish you luck.