Well, the very earliest behaviourists didnt believe in thinking or at least believed there was no scientific or therapeutic worth in introspective or speculation about thinking and thought processes, the cognitivists, to the best of my understanding, only really came into being a force when artificial intelligene and computer programming started to develop and require a model of processing or "thinking". I think that's a bit mad, I could have it wrong or muddled because its a while since I read it but I dont think that programming analogues for human beings are perfect.
What sort of behaviour modification are you going to use? Is the use of close family as test subjects to get you to self-reflect? On the ethics, partiality etc. Will you use aversion therapy or rewards conditioning to effect a change in non-compliance?
My views about behaviourism are pretty much summed up in the toon in my profile of the dog and Pavlov, there is a saying that the mice performing stunts for their cheese were actually conditioning the scientists conducting the experiments, I think this holds true and only hints at the radically reciprocal and systematic nature of behaviour and motivation. Behaviour modification is over simplified but I do believe that even when properly understood or done well/ethically/competently the possibility of it traumatising or corrupting both parties remains.
All research into therapy has indicated that quite apart from the techniques or methodologies involved, which can be very, very different from one another, that it is the relationship involved between each party to the work which is of vital importance and I think that behaviour modification programmes only damage relationships and capacities or opportunities to relate. That relating is vital to anyone and on going, in some people it manifests itself wrongly or oddly because of their early life experiences and how that's lead to attachment seeking being patterned on to their brain.
Often the real conditioning involved is about power, recognising power, valuing power, subjects learn about obeying power until you can exercise it yourself in a different capacity or context and this gives rise to what Eric Fromm talked about in Fear of Freedom especially. Authoritarian personas who are obediently submissive to a superiors and tyranising towards subordinates in order to relieve anxieties and uncertainty.
All that said I think the theory is good, if only because other theories have been developed in contrast with it, and I also think that it does a great service in highlighting, no matter how imperfectly, the role of stimulus and conditioning as a determinant of behaviour or habits at the very least.