Dipping is ridiculous and should be removed completely, at least from a reality standpoint. (I know it's a game...but still)
The only non-magical melee weapon that should benefit from being on fire is a torch. If I hit you with an unlit torch, 1d4 damage. If the torch is lit, 2d4 damage because the fuel oil that's keeping the torch alight can spatter all over you, do instant flaming damage, and possibly set you on fire. Cool, great.
If I hit you with a meter long, razor sharp sword, having some flaming oil on it isn't going to do ANY extra damage to you. That's absolutely ridiculous. Wooden blunt weapons, as someone else also said, shouldn't be a thing, unless it's soaked in oil first and then useless after one combat. Then maybe...
If I shoot you with a flaming arrow or crossbow bolt, please trust me, it not going to be ANY more damaging if the projectile is on fire. It's going to have ZERO chance of setting you on fire. And, unless it's a special, super heavy, blunt arrow with an oil soaked rag wrapped around the end (making range go way down and accuracy nearly non-existent) the flame is going to go out as soon as you fire it.
Dipping projectile weapons is stupid to put it nicely.
On the other hand...give us slings as a weapon and special ammo that could explode on contact, THAT makes sense. In place of a heavy metal projectile or stone, it could be a clay shell made containing flammable gel, alchemist fire, etc.
Rant over...
