Ann,
There are great many opinions out there and many ways to answer them. I'll give you my two cents as I have studied and have been competing in both styles. Furthermore, I am a dance DVD junkie and have a very large collection of them from all over the world.
Allow me to share my experience with you. First comment on the styles. I believe and in practice that you can do both styles socially and competitively. And yes, you can dance Standard Foxtrot socially; it is a matter of skills. The major difference is closed hold at all times in Standard and mixed mode in Smooth. The other major difference in the tempi of the music. According to the competition syllabus Waltz is the same, Standard Foxtrot is 28-29 and Smooth is 30-32, Standard Tango is danced at 32 and Smooth is 30. Viennese Waltz in Standard is 59-60 and Smooth is 52-54. There is no Quickstep in the Smooth curriculum as of yet.
There are technical differences in the individual figures and syllabus steps between the two disciplines. But as a new dancer it not come to play much of a role especially in the social setting. And, this is not a place to get into that level of detail.
One style will not prohibit or hinder the other; in fact, they complement each other. In Standard, the technique of dancing in closed hold with help the Smooth closed positions and Smooth individual balance and movement helps personal balance and independence and personal expressions. The basics of the dance, balance, posture, hold, moving the center through the feet, and setting one feet in front of there is used in both styles just the same.
As for dance DVDs, it has been mentioned before, they can be an aid and supplement. Relying solely on video training will guarantee you the opposite of what you are looking for. There is no "feel" involved in the video. An Instructor, as gifted as they may be, will not be able to communicate that feeling to you. And more importantly, what you see in demos and instructional dance videos, is never what you think you are seeing or it is what you think it is. There is so much going on inside those frames that is not possible to discuss in the video.
These videos are produced by some of the best in the field; they will make it look easy and simple. That is what they do. They take things for granted most of the times and there is never enough time to break things down as they should. No one will sit through them.
Here is how I use tapes. After of about a year of serious dancing with private and group lessons. I began to understand the elements and basics that I needed to learn to be a better dancer. I watched tapes and demos. Looked that the choreography and interesting figures I wished to learn. I took those materials to my coaches and asked them for direction, clarification, and explanation. My coaches appreciate the fact that I do not try to learn new material on my own and they have to undo and redo them. After 4 years, I have a better sense of what is being presented in the video lectures and which areas I can do on my own and which areas I am clueless.
Nothing will EVER and I mean EVER takes the place of one on one coaching with a well qualified coach. As a beginner, the group classes and dance partied were the only sure way to get comfortable on the dance floor and retain what was being taught. Especially if you are a social dancer this is the ONLY way to learn. As a competitor things change in a dramatic way.
Well, I hope you get him on the dance floor and in the group classes quickly. I am an engineer and know exactly what you and your coaches are going to deal with. After four years, I am just allowing myself to shut my head off and just listen and allow the music to dictate what I must do. This is an art after all and should be treated that way. It is very difficult for people like us not break things down so much. If I danced like I think, I would dance like a robot (as I did for a while). My dancing was very technical, careful, and mechanical. It was not artistic or flowy ; movement was small and ridged. Make him aware of this. He can think his way through it with analysis, but he will be a paralyzed dancer. Once he lets go of it, he and you will enjoy it soooooooooooo much more.
Well here is my two cents……….good luck with coaching and happy dancing…….reza.