Rockhillmanor - I wasn't suggesting that any of those things are problems in and of themselves. A shy sheltie is not a problem. A shy sheltie whose owner doesn't socialize the dog is likely to become a problem. Not because of a fault in the dog - but because of the failure of the owner to address the shyness appropriately.
The problems ARE the fault of the owners.
An example of what I'm saying: I had a very pretty and sweet husky/shepherd mix as a foster. After several days with no problems, I left her with my 2 dogs to go to work. Within 2 hours, she had torn a hole in the chain link fence to the enclosed cat run, jumped through the window into the house, played in the inside water bowl until water was all over the floor, went back out through the window and hole and was happily playing outside with the other dogs when I came home (2 hours).
Now this dog looked very much like a shepherd, but her personality traits were pure husky. She had many people interested in her, but I insisted on a home that would provide tons of mental stimulation. She went to live with the couple who read everything on huskies they could find, established an agility course in their backyard, enrolled her in agility courses, etc. The other homes would have failed the first time her husky brain saw a challenge.