Custom Liquid questions (Finite fluid / Farmland-like liquid detection / exploding into area of fire)

Hi. If you've seen my other post here, you'll know that I'm adding apocalypse-themed blocks and items. I'm currently working on Gasoline. I have it largely behaving how I need it to, but I've hit a couple problems I don't currently know how to solve.

1.) I want the fluid to be finite. Instead of having a source block that flows endlessly, it should spread out and disappear immediately. Maybe I could add some type of procedure for the block to replace itself with air after an amount of time?

2.) I want blocks touched by the liquid gasoline to become flammable. This seems simple enough, but I don't want them to burn away to nothing if they weren't flammable before. Non-flammable blocks would catch fire, and spread fire to other blocks while on fire, but shouldn't burn up. Sort of like how the Smithing Table is. This effect would ideally be a block tag or something similar that removes itself randomly after a while.

3.) When the gasoline is destroyed by an explosion, I want it to explode more and leave behind fire. This explosion part works, and creates satisfying chain reactions wherever the gasoline flows. Unfortunately my setup to make it then create fire does not work. I have a screenshot but I don't see a way to attach the image. Let me know if there's a way or if I just have to place a link to it.

Thank you for any help you can give me with this matter. I know the complexity I'm aiming for is beyond MCreator's current capabilities, but I'm hoping to make as much of it in this as possible before I resort to pure coding.