Could we get some options to tweak the turret ourselves according to our mod setup? Something like water pressure/speed, damage inflicted, max range, enemy slow-down factor, etc...
Water pressure/speed? Not sure how to set this, but if possible, I could add this. Enemy slow-down factor is possible. I'm very reluctant about inflicted damage and max range, though!
For version 1.0.0, I already have restored the setting to make spawners and worms immune to water and steam damage (it won't depend on scripting, but is defined in the prototypes). There's also a setting to allow water turrets that use water to prioritize fires over enemies or vice versa; as this requires scripted targetting, this will be disabled by default, so the game will automatically choose a target, thus saving on UPS.
Delegating as much as possible to the main game and saving UPS is the main thing for the 1.0 release. Allowing players to change the range of turrets would contradict this because turrets that are looking for fires will have to search an area on the surface that will increase with range. Also, the probability that more fires are found (and have to be managed by the mod) if auto-targetting is off will increase with growing range. This could be a performance issue if many water turrets are used.
I'm against changing the inflicted damage because that would throw everything off-balance for now. I use dummies to mark fires. They have just 2HP, but given the minimal damage that water turrets cause, it still takes 300-400 ticks to put out one fire (which is too much, I think). But if the damage was raised just a little bit, the time needed to extinguish a fire would sink to almost nothing. There may be other ways, though (e.g. increasing max_health of the fire dummies proportional to the inflicted damage, or making enemy entities more vulnerable to damage from water and steam). I'll have to think about it, perhaps it is possible after all. :-)