Okay, I've played with it a bit more, and have more feedback (constructive, I understand nothing works all the time
Here's what I've gathered:
-Turning the engine on and off is rather inconvenient using the default mapping, so I remapped it to a single key (Z) and it works better for me, personally.
-It wasn't made clear but yes, it seems E is the key that makes you fill your car up... despite it even saying in the .ini file that R is the key for it?
-Holding E down fills it continuously, which is good because I was afraid I'd be sitting there hammering E to get my car filled.
-One big issue right now, is you can't see the fuel gauge while you're filling it up, which leads me to a lot of getting in and out of the car to see how much I've put in.
-In my opinion, gas isn't used fast enough. If it was consumed twice as quickly, it really wouldn't hurt anything. As it is, if your fuel bar is orange, you can still do a few laps back and forth across all the islands without worrying about running out. That's actually my biggest complaint right now, is there's never a reason to fill the car up unless you're driving around for like two hours IRL.
So in total, here's what I'd like to see changed in future versions:
1) Either increase the consumption rate or let us change it via the .ini file.
2) Letting us pick our own fuel costs via the .ini is goooood, leave it in.
3) The bars need to be less obtrusive.
Also, a question: Is this mod changing how much damage my car can take? It feels like my cars are catching fire a lot faster... which is obviously not a good thing.