I have 2 mini Schnauzers. We got both before they were 2 months old. Our little girl has never thought about biting or growling at us unless we hurt her while trying to comb her hair or clean out her ears. She is very tender. She sits near us on her own terms. Sometimes, she demands attention, but most of the time, she is just in the room.
On the other hand....the boy has to be gently woken. He will growl and bite in a heartbeat. I can promise you he has never been abused in any way...spoiled, rotten dogs. They are both very good at ignoring us, very similar to a cat, if they don't think we are offering food.
Almost all the small dogs I know are very cat-like. I love what you are doing with this little dog and know that you will have success. I am like the others, just take your time and let the dog come to you. Treats are the only way ours really pay attention to us. They are very independent.