Long time lurker here. I finally signed up just now out of, I don't know, clarified butter solidarity. (Okay, I may have also had a glass or two of wine.)
I think mainly the inconsistencies in recommended heat have to do with the difference between gas and electric. If you have gas, you can go from medium-high to low and the effect is immediate; if you have electric, the heat dissipates slowly, so if you start high, you need to completely remove your pan from the heat source in order to keep from burning.
My personal approach for ghee has been this. Heat on medium high until the butter starts to foam, then immediately remove from heat. Skim the foam off the top with a tea strainer. At this point you have clarified butter; to go from this to proper ghee, strain it completely, let it cool for a minute or two, then heat it up again and start over from the beginning. The second time you can heat it higher, because with fewer milk solids you can afford to burn it a little without affecting the flavor.