3) Yeah, thats a good idea. A "same as last week" button and a "copy week" button would be great. This can only happen once you re-design the workflow though... I imagine it such that you click a "add a new week" button and then fill it in, so once you do that, you can have these buttons.
4) Yeah. A warning if someone enters something thats not a number/integer, but a field is better (I prefer red text saying "this should be a number" that comes up next to the field, but thats up to you).
5) Even still. If I put up a workout, who will be editing it? How do I know they'll be editing it in a way thats really in the spirit of the original workout. What if a professional weightlifter comes in and starts making the workout more hard core? It might be "better" but not really good for a certain kind of audience?
This is not to say you can't find a way around this. You may want to consider how people get "access" to a workout. If you do restrict access though, a discussion page would be good. I don't see this as an immediate issue, but something you should keep in the back of you mind and think about as you go forward.
6) :) Its just the fact that your a "computer person" so an "index" is something you think about.
P.S. Its good that your taking all the feedback positively.
