She is highly sensitive, insecure, over-bonded, demanding and untrusting - I am sure this also comes with being very loving & smart.
This is the kind of dog that needs you to behave in a very specific way.
She has learned that running away from things that make her nervous works, so she does it more. It becomes her habit - get nervous = flight. So having her on the leash when she is in an unsettling circumstance will help her face the music and learn through repetition that life really isn't so scary. You need to create lots of opportunities for her to face her fears in a positive manner. Don't force things on her or create drama around the events, you need to show confidence and she will learn from you.
You need to work on a good long down stay. As you go about your life she needs to NOT follow you everywhere, which means that you are going to have to ask her to stay as you go from room to room - desensitizing her to your coming and going. She is too dependent on you and you have become her security blanket.
Crate training would be highly recommended for her, but that means lots of short sessions and building to longer sessions in the crate when you are home. If you don't like the crate idea then put her in her special area more frequently throughout the day and then practice coming a going a ton. No goodbyes or hellos as you go about your business. You need to come and go so often she gets bored. If she complains with any amount of drama then you need to correct her. It will take 3-5 corrections before she connects the dots. "Oh, every time I bark mom says 'No bark', hmmmm, she must not like my barking" I will be quiet and see what happens. Oh, I got quiet and then after a few minutes she let me out. So being quiet is what works!!!!"
People should not give her any attention when they first greet her. Ignore her. If they insist on greeting her then the person should not look at her at all as they crouch down and play with something on the ground (a pebble) or just look everywhere but at the dog. The dog should relax and attempt to sniff the person. If the person feels comfortable they can calmly and gently stroke the side of the dogs face for just a few seconds then stop. Let the dog know that the person means no harm. If the person is willing they should take her on the leash for as long a possible - 30 mins, 1 hr etc. It gives her brain a great chance to get through the flight response repetitively, learn to stay calm and maybe even enjoy the interaction. Then give her a break in her area, but repeat it after she has had some down time to process the interaction. Each time this happens she should adjust faster and faster as her brain reminds her that this is a safe thing to do.
The bigger her vocabulary the better - so general obedience is going to be handy. The more she knows and the better she listens to you the faster you can help her get through these challenging times. If she is in the habit of listening to you throughout the day then when she is anxious she should look to you for help and you will be ready with the answer. She needs you to lead the way. She is too insecure to figure this out on her own.
Listen to our podcast on Bubble/boundary training. It will help you understand her. She has a huge personal bubble because she is nervous about her safety when people start to press on her bubble - so she keeps it really big. When she decides to trust someone in her bubble then she doesn't want them to leave (mostly you). It's almost like she has 2 bubbles. One is huge and the other is tiny. The big one protects her from scary people, and the little one holds those who are trust worthy near her. Hope that makes sense.
Call if you need more help.