I don't have my Trollpak or Wyrms Footnotes 7 (or 8. where I think it originally was printed).
iirc, The pitch is roughly rectangular with two triangles (the keeper's area) at either end around the scoring area. I'm not sure metal armour is allowed, but leather certainly is. The "ball" is a live trollkin, replaced if it dies, at the refs are, indeed, two giants who kick offenders off the pitch (one kick - but that hurts!).
No healing is allowed _on_ the pitch, but teammates can carry the injured to the side line to receive healing.
I think there were between 5 - 7 trolls to a team. When we played it it never looked like US football, more like a mix between soccer and netball...
Ranges for throwing trollkin - can't remember. Perhaps STR-SIZm. Not sure how far a trollkin can be kicked, either.