Dancing Hoskuld
Deity
I request in advance that there be an on/off option for these new things in the Custom game options.
I think your going to be better with a fire control civic that makes/lets you build ordinance (not building buildings that require a civic to function) in your cities. Which means revoltions to change civics increase the risk of fires as your not paying people to not let that happen. Unless your running the ordinance bucket brigades and then volenteer fire fighters.
Also, I think you'd be best off making the ordinance per town build issue. Make a new national project thing only opens up the options. Then go for the civic at first.
If your adding in flamability, make sure its also a combat mechanic... C2C has arsonists as a long term unit after all... though using fire as a weapon should risk causing unit killing fires on plant filled tiles. Crispy Stacks of Doom. Also that means adding in wildfires/forest fires that are hard to put out until you get fire fighting units. unit starting with works and then to professionals are needs to stop this mess.... which means storms and such causing fires with lightning.
In short, that is a giant can-o-worms your opening.
then there is fire ships and fire balloons.