Is it proper to have an informal relationship with your Ph.D supervisor(s)? Can this be an advantage or a disadvantage? And can this relationship create the desire academic intellectualism or otherwise?
There are always pros and cons for every decision being made. It is very hard to make any conclusion as it depends on case-by-case basis. It is totally based on the mutual interaction between the researcher and the supervisor.
I don't know whether an informal relationship is proper or not, by my major professor and I were the only two guys in the business school that played golf. We teamed up and played in about 20 team events per season. It was an advantage for me because my share of our winnings kept me in new clothes, and later we placed a couple of papers in very good journals.