Schedule 1 also requires that there is no medical use for the drug, which IIRC ethanol is an effective treatment for someone who has consumed methanol.
Technically yes, but that didn't stop marijuana from being schedule 1. Actually, isn't it still schedule 1 in the US?
https://www.dea.gov/drug-information/drug-scheduling
The key phrase is "currently accepted medical use". That is an arbitrary definition that is set by the regulator. A drug must have a medical use that is accepted by the DEA who defers to the FDA for such definitions.
Hell, even meth can be prescribed by a doctor; I believe the brand for it's called Desoxyn and it's usually prescribed for severe overeating disorders, not usually ADHD.