theres a No HUD codes out there. Search SSBB Hack Codes and click on VirusTsunami's Code pack, it has almost all the good codes. Including all the codes needed for Brawl Machinima
The NO HUD code only removes stocks, damage icons, and the little thing that says what players you are. The No Tag code just removes the image that appears behind the damage icons.
The timer is obviously controlled by another source, there are a couple of codes (I can't remember where I saw them) that make the timer partially transparent, but none that make it completely invisible :l