My advice would be exactly the opposite, let them do what they want, interact, but as passively as possible ... you will probably find that people actually prefer the more candid shots anyway!
I think you have the lighting perfect, I have a similar set up, but i actually tend to rely on natural light... its easier, but my shots do lack the separation from the background that you have achieved!
I am a BIG lightroom fan! its by far the best tool i have used, but then it was also the first of its kind i used so i may be saying the same about aperture or capture one etc if i had started with any of them!
what i have liked about it most is the fact that it has seemed to grow with me as a photographer (ive been using it since version 1) I would go as far to say that it has actually tought me a thing or too ... which is a strange thing to say about a piece of software! It has certainly allowed my style to develop freely i think!