Apok.pt: you make some good points and it explains why it may have been left out of the game. However, the recipes that rely upon Fire Arrowhead such as Steam & Explosive have a lower crafting level (CR2 & CR3 respectively). Perhaps... perhaps we should consider forcing players to us alternative sources of fire (telekinesis + candles?) when low on fire arrows?
With regards to the smokescreen I wasn't thinking of the balance changes, but sticking with existing crafting requirements, i.e., CR1 to make a smoke arrow. I admit that the arrow is very good, but the trend of recipes for arrows is that arrowhead crafting level = arrow crafting level.