Thanks for setting up a pool and creating a forum account. To answer your question, Yes the trades have to be input into the system by the administrator. We have big aspirations of making it so all poolies can handle their own rosters but that has not materialized yet.
One other question. In terms of positions, do they matter? Does it matter how many centers you have, or how many LW's you have? I thought it did, but I cannot find it anywhere.
One other thing; if the admin put most of the emphasis on defensmen(more points coming from the D position), it would be wise to draft more d-men then correct?
It doesn't matter to the system how many centers you have. The system just clasifies centers, and wingers together as "forwards".
Without knowing more about your pool I would say that your assessment of the scenario is correct - it would be wiser to draft more d-men if they get more points.
This is one of the pools you really want to do if not every one is a hockey nut; if you want to make trades and lots of crazy head to head matchups use Yahoo. Both pools are best for hockey :D