I guess dave_hat's class is for, at least, intermediate dancers, who can danced basic step quite "naturally". I think they never teach Body Contact to absolutely beginners. Those should focus only on which leg/foot to move, counting and timing, knowing the basic hold and poise, moving with partners.
Body Contact should be introduced early, of course not too early. But learners are not required to do it exactly the same as the "true" technique. They only need to know what is correct, and do as much as they can. It's applicable for one year experienced dancers and higher, and necessary for really serious ones only.
No I don't think body contact is heavy. Just enough for both dancers "feel" the move and rhythm of each other. Right, enough to establish connection. About legs contact, I sometimes feel, but can't admit whether it always happens (constant contact) or not.
One comment about body contact in PP: for me it is "Right" to "Center". When in Closed Position, it is slightly R to R (Man's R side to Lady's R side). Therefore, when "switch" to PP, keeping the frame stable, Lady's body will "roll" to Centre, not to L side since it is too far. Any comments?
Best regards,
MSN