Sorry to slightly disagree Tightslot, but having studied Ergonomics at University, and particularly the impact of pax environment on crash survivabilities, I feel I can speak with some authority. As a short-legged, long bodied person, in a fully forward lean, the distance from the top of my head to hip fulcrum is more than 29". It is therefore not possible to achieve the optimum position with a seat pitch of 29" (or 31" for that matter), and I'm only 5'9". The compromise that the "authorities" seem to find acceptable is therefore to have the forehead up against the seat in front (to reduce impact injury). Unfortunately, that dramatically increases the chance of a broken neck. Even worse is the picture that you still see with some carriers, with the face/forehead up against the seat back upper.
However, the first point that you mention about foot position is so important. It is smashed shins that will prevent a survivor getting out, and this has proven to be the case in so many accidents involving fire etc. Even with impact only accidents such as Kegworth, many more would have been walking wounded rather than requiring evacuation (and then long term debilitating injury) had they had their feet tucked in as you describe. I automatically get my feet into this position in any take-off and landing just in case. Emphasising this in the safety demo and safety card pics might be more useful than the rest of the brace position.