I just wanted to add a couple pieces of information.
Someone earlier in this thread said that toxic alcohols are added to ethyl alcohol to avoid taxation. This is normally true, but I don't know where you are located but in my region, the breweries were given a legal pass for producing pure ethyl alcohol for use in hand sanitizers when there was a shortage of sanitizer. So you had commercial food grade ethyl alcohol being funneled toward hand sanitizer production. This meant the purity was relatively high even if it didn't get the official "food grade" certification.
So I think it depends on who is producing what you're buying. If that 70% ethyl alcohol comes from a brewery or another local company that was given temporary licensing for sanitizer production, then you might be dealing with a high purity product. I reason this because a food grade company is not going to change their manufacturing apparatus because of a temporary license -- it would cost them money to do so. So they will just keep making food grade alcohol for sanitizer.
Your elevated liver enzymes could be due to alcohol dependence in general. Methyl alcohol, even in small amounts, usually results in blindness fairly quickly if there is regular consumption. Isopropyl alcohol requires large consumption to die from and its main drawback is that it's a more effective central nervous system depressant than the ethyl form. But in trace amounts, it's doubtful that it will harm you. If you ever get a fruity taste in your mouth after you're done drinking, that's probably the isopropyl form converting to acetone in the body... which is a positive test for isopropyl alcohol. But normally, you'd have to drink a decent quantity of just isopropyl to get that effect.
I'm not encouraging you to drink hand sanitizer but if you've been doing it for this long and haven't gone blind, had a nervous system reaction, or puked/shit your guts out, then you are either not consuming toxic forms of alcohol or the quantities are so small that they are negligible.
You should stop though. The formula you're drinking may be relatively safe but it could change at any time because it's not "food grade" and they don't have to warn you if they change it.
