Any container that can hold water can now hold fuel. and are ignitable releasing an explosion proportional to the amount of fuel in the container. Maybe a full bottle can be equivilant to that of a molov.
The new dynamics as a result can get indepth and add a great deal of creativity for content.
-a player can throw a bottle and shoot it with a fire arrow for a small explosion and fire.
-a player can throw fuel on another player from a bucket and set them on fire with a torch for a limited time.
-a player can throw a jug of fuel, or leave one on the floor by a door so that they can shoot it with a fire arrow when a player comes out.
-a player can go suicied attack with a fuel bucket and a torch out.
-a molotov can be placed on the floor and ignited later on.
with this i also think pressure plates should provide enough power for a 75% chance that an ignighter goes off.
-a player can leave a fuel container by an ignighter, connected to a hidden pressure pad for a very basic flame trap