Hi Cathy,
I will not be much help on this subject. After dealing with my Senegal, I can tell you that Jamie really does not have any negative traits when dealing with people she knows.
Having said that, I established with her that I am the flock leader and that she has to do things (or NOT to do things) if I don't want her to. Just be consistent in your behaviour. If you give in sometimes, the bird will just be confused. Pet birds really need a person to look up to and follow.
Caiques generally like to surf in people's hair! Jamie doesn't but sometimes she lands on my head or sits there when I brush my teeth. Birds on shoulders (or higher) should be generally discouraged because they think that they are on the same level (with your shoulder being the perch). Another reason is that they could give you a serious facial bite.
But you just have to get to know your bird. My Senegal is never allowed on my shoulder. He is happy to sit on my knee and does not even try to climb up my shoulder anymore. This is because I was consistent. He does try it with new people - birds always try to push our limits. You are the one who has to establish the rules and boundaries.
Jamie is totally different. I can have her on my shoulder or my head anytime and she does not bite. Now this may change at some point (for example due to raging hormones) but she has been great in the past 2.5 years. She really enjoys riding on my shoulder because she can be with me a lot (even when I have both hands full or I'm doing someting).
But back to your question. I would say that biting, excessive screaming and plucking are the most common things to watch out for - like with any bird. Every situation is different and there is usually no quick answer. If a particular behaviou starts, it's best to start dealing with it right away before it becomes a pattern.
Good luck and don't worry too much - just have fun with your baby
Kate