The tolls Iran charged/ propose charging appears to be $1 per barrel. This comes from a 2 million barrel tanker being charged $2 million, and there was a smaller tanker charged less. What tolls Turd wanted to charge with his "joint venture", no idea. Although he has abandoned that.
Prewar we were about $70 per barrel. Now we are oscillating about $100. If the war ended today and normal service resumed, the toll, if it happens, would be near insignificant.
Iran charging the tolls would be illegal under UNCLOS, because freedom of navigation. However, the punishment for breaking UN law would be sanctions. And given that Iran is already sanctioned to the hilt and beyond ( the beyond being US unilateral sanctions), I don't think there is anything anyone could do.
However, the oil folk are saying that if the war ended today, it would take 2 years to get back to "normal".
Aviation fuel supply is a separate thing really, in a way. I can't get any info about that on my web. So we need the expertise of @notimagain . My understanding is that aviation fuel, esp jet fuel, is actually a pretty coarse thing. It's not as refined as petrol for example. So likes of Europe does not actually produce a lot. It's largely imported, because of economics. It's cheaper to refine it elsewhere and ship it as a finished product, rather than as raw crude ? But even then, it gets more complex because some airports are close to refineries, and in that case it makes economic sense to produce it locally and pipe it. Other airports need to import it, and it is piped from the docks to the airport I think. AND... this all plays a part in airport location too. Planes, especially long haul, use a lot of fuel.
Capitalism at work. Makes my head spin so it does.