My boss has told me on several occasions that I am the glue that holds the office together.  I think the skill that is necessary is one we all have if we choose to use it - empathy.  I try to always see both sides of the picture and this is becoming more and more important dealing with very young staff up to mature workers on the cusp of retirement (me).   

I work hard to find the common denominator with each person in the department and try to build on it and develop a good working relationship.  Our last employee survey results were the highest in the organization in terms of employee satisfaction and overall morale - no small feat as we have approx. 300 employees.  Decent pay, good benefits, etc. all matter but if employees are disconnected one from the other - nothing works well!

My boss and I are opposites but we have a great working relationship.  I think it's because I listen more than I speak.  I've found after many years in this field that often our senior managers just need to vent and they need to do so with someone they trust.  I sense that your boss is picking up on your body language as it does come through loud and clear in your post - don't get too close!  Nothing wrong with that but I think we get back what we put out.  I am not that interested in developing a personal relationship with my boss.  I have that with my family, friends and select co-workers.  My supervisor and I share superficial aspects of our personal lives such as where we went on the weekend, a bit of family news, etc. but I would never share any personal problems with him unless they were work related.  

If you are able to do your job with the relationship you now have with your boss that should be sufficient.  Not everyone likes to be  "buddy-buddy"!