Like campfires torches should be extinguishable by throwing a splash water bottle on them. Campfires will be lighted if they are shot with burning projectiles (flame arrow, blaze fireball, ghast fireball...) so that should apply to torches too. Would be fun to try and light torches by shooting them with arrows from far away.

Could be cool, but pretty low priority right now. Would be a bit more difficult to code than other things and it's not essential, but it would be cool to have eventually.