It doesn't seem to have been mentioned, but I'm only 64 seconds into the video and you made an error. You said it had 5K watts running, and that is not correct. That 5K rating is for peak watts, but is only 3900 running watts.
With your shirt having Los Angeles on it, some things to consider that is both relevant and not relevant to location: 1. First thing is first, change out the spark plug for something better like an NTK. I couldn't find the NTK plug that was right for my generator, so I ended up with a champion. You talk about how your generator was running like crap under no load. Yeah, the stock spark plug they put in these generators from China will do just that straight out of the box. They are really that bad. 2. I don't know why you are going on about high octane fuel. In California they stick a certain fraction of the fuel as ethanol pretty much no matter what. Then when you look at the pipelines moving the gasoline around, they are not labelled Arco, Cheveron, etc. It all goes through the same pipe and then you have some slight variations additives. One can argue that one gas station is a little bit better about their additives than others, but really all of these brand labels are closer together than you probably think because they all share the same gasoline pipeline. 3. From what I have seen gasoline doing to these small engines and you even have some idea of what it is doing to the engine, why would you buy a dual fuel generator and then run it on gasoline, especially run out and buy really expensive gasoline that doesn't have the corn ethanol in there to ruin your small engine with? Why not use propane seeing it can run on that and do it well? At least in LA, you can say go out and get a 30 lb tank, bring it to your local propane refueling station, and fuel it up for not much more than 87 gasoline at the local gas station. That 30 lb tank will last as long as a full tank of gasoline on the generator. If you need a lot of run time, maybe even go for a 100 lb tank. (For an extra amount, you can get a 100 lb tank with a wheel kit on it.) Just don't forget to do the regular maintenance on the generator. 4. For running on propane, here are some things to consider. You just hook up the propane tank, make sure the fuel selector is in the right position, do a quick leak check, and off to the races you go. When you are done, just shut down and unhook. Looking to put the generator into storage for a while, great, just stuff it into storage and you are good until the oil in the engine goes bad. For generator maintenance, seeing propane is a gas that burns cleanly in the generator, you don't have much in the way of buildups in the generator and you certainly never have any issues with the carburetor as propane basically bypasses the carburetor. I mean especially in an emergency situation, you want your generator to just start up and go, which is exactly what you get with propane. Gasoline is a lot more problematic on all of these fronts. 5. This is a "floating neutral" generator. You are running things in a bit of an unsafe way there by not having a ground-neutral bond. You can get a cheap bonding plug on Amazon, granted it probably would be best to pop the hood and bond it the right way. The reason why you want to have a ground - neutral bond is per NEC codes, you want short circuit power to return to source over low resistance wire and pop the breaker.