great feedback,before I suggest things I would like to see in the finished spec mode, It would be best of you guys get the foundation and basics down(aim delay, cam controls, hotkeys, UI basics-HP-ammo-time left/time to beat-cooldowns, map overview).
From there things like instant replay, slow mo, movable and customize-able UI ( think Sc2 Gameheart), team flair and icons (dota 2) .