Hi Kiran.
:) 'behavioural' Interviews are nothing but aimed to probe the behaviour of a person. Well the obvious question is what's behaviour ? Probably a mixed effect of a person's genotype (the properties that are inherited from genes), the phenotype (properties derived from environment). When dealing with organizational system, a lot of such variables are present that often alter your behavior. Such as you are talking with your friend, consider two different situations - presence and absence of your boss.
Probably that's an oversimplification. Its a matter that mostly Organizational Psychologists deal with. To answer your query- yes, its definitely better than normal interviews in some aspects as they are meant to 'probe' certain idenfied areas and not others. To find a better result, you probably would want to do a comprehensive structural probing (and unfortunately your resources will not permit you).
Hence we are still going with normal interviews in our daily life to save costs and money.
As such there are no bad or good questions in an interviews, everything is planned and structured. For example if you are using a 'funnelling' structure - i.e., starting with a varierty of topics and then slowly proceeding with specific ones .. that may not work with 'diamond' structure which starts from specific points, touches a variety of points and again backs to some other (predefined) point.
This is an art and psychologists strive to gain mastery over it.
:arrow: Probably I could not satisfy your query (because question is general in nature, and not indicating any special reference in which behavioural interview is to be used).